{"product_id":"hella-marine-7537-24v-21-5w-bay15d-bulb-10-pack","title":"Hella Marine 7537 24V 21\/5W BAY15d Bulb, 10-Pack","description":"\u003cp class=\"nvn-hero\"\u003eThe Hella Marine 7537 is a clear halogen stop and tail bulb for 24-volt systems, sold as a pack of 10. It's a dual-filament 21\/5W bulb on a BAY15d bayonet base in the standard S8 shape. Built to Hella Marine's fit-and-forget standard, it's the honest replacement for the rear combination lamps on larger 24V boats and commercial rigs.\u003c\/p\u003e\n\n\u003cdiv class=\"nvn-description\"\u003e\n\u003cp\u003eThis is the Hella Marine 7537, a clear halogen stop and tail bulb built for 24-volt electrical systems and sold here as a pack of 10. It runs 21 watts on the brake filament and 5 watts on the running-light filament, uses a BAY15d bayonet base, and comes in the common S8 envelope. If you've got a 24V rig and a drawer full of blown rear bulbs, this is the box you keep on the shelf.\u003c\/p\u003e\n\u003cp\u003eLet's be clear about the voltage up front, because it matters. This is a 24-volt bulb. It is not a 12-volt part. Most trailerable boats and smaller center consoles run 12V, so this one isn't for them. Where you'll see 24V is on larger vessels, commercial boats, and heavy rigs that run a 24-volt house or chassis system. If your boat or truck is wired 12V, you want the 12-volt version of this bulb instead. Put a 24V bulb on a 12V circuit and it stays dim, and a 12V bulb on a 24V circuit burns out fast. Check your system before you order.\u003c\/p\u003e\n\u003cp\u003eThe 21\/5W rating tells you this is a dual-filament bulb. One filament is the bright 21-watt element for your stop light or turn signal, and the other is the dimmer 5-watt element for the running or tail light. That's why it rides on a BAY15d base. The two pins on a BAY15d are offset on purpose, staggered so the bulb only drops into the socket one way, keeping the bright and dim filaments wired to the right circuits. You can't get it backwards. It's the same style base you'll find on a standard 1157 or 1034 dual-filament bulb, just rated for 24 volts here.\u003c\/p\u003e\n\u003cp\u003eThe S8 shape is the familiar straight-sided glass envelope about an inch across, so it fits the same combination tail-light housings these dual-filament bulbs have lived in for decades. The glass is clear, which gives you clean, true light output and lets the lens color do the work. Halogen keeps the light bright and consistent over the life of the filament. A clear bulb behind a red lens reads red, behind an amber lens reads amber, so one part number covers stop, tail, and turn duty depending on where it sits in the housing.\u003c\/p\u003e\n\u003cp\u003eBuying a 10-pack is just practical. Rear bulbs are the ones that go, and they rarely go one at a time. Keep a few in the console or the tool kit and you're never stuck with a dead brake light at the ramp or on the road. A blown stop light is also one of the fastest ways to get pulled over or flagged on a safety check, so it's worth staying ahead of. At this price, stocking a full box is cheaper than chasing a single bulb when you need it.\u003c\/p\u003e\n\u003cp\u003eHella Marine builds these to a fit-and-forget standard, and that reputation is earned. The company's roots are in vehicle lighting, and the marine line carries that same focus on materials that hold up to vibration, heat, and the kind of punishment a rear lamp housing sees. These are built for the marine environment, so they shrug off the moisture and shaking that kill cheaper bulbs early. Swap one in and you shouldn't have to think about it again for a long while.\u003c\/p\u003e\n\u003cp\u003eInstallation is about as simple as it gets. Kill the power, pull the lens or access the housing, push the old bulb in and give it a quarter turn to release, then drop the 7537 into the offset-pin socket and twist it home. No tools, no wiring. If a new bulb still won't light, check the socket contacts and ground before you blame the bulb. Nine times out of ten a dead tail light is corrosion, not the glass.\u003c\/p\u003e\n\u003cp\u003eOne more fit note. Because this is a BAY15d double-contact base, it won't seat in a single-contact BA15s socket, and the offset pins won't line up with a parallel-pin base. Make sure your housing actually uses a dual-filament BAY15d bulb before you order. If it does, and it's a 24-volt system, this is the honest, no-drama replacement.\u003c\/p\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eKey Features\u003c\/h2\u003e\n\u003cul class=\"nvn-features\"\u003e\n  \u003cli\u003e24-volt rating, built specifically for boats and rigs running a 24V electrical system\u003c\/li\u003e\n  \u003cli\u003e21\/5W dual filament, one bright element for stop\/turn and one dim element for the running light\u003c\/li\u003e\n  \u003cli\u003eBAY15d double-contact base with offset pins, so it only seats one way and the filaments stay on the right circuits\u003c\/li\u003e\n  \u003cli\u003eS8 clear glass envelope, the standard straight-sided shape that drops into common combination tail-light housings\u003c\/li\u003e\n  \u003cli\u003eHalogen element for bright, consistent output over the life of the bulb\u003c\/li\u003e\n  \u003cli\u003eClear glass lets the lens color do the work, so one part covers stop, tail, and turn duty\u003c\/li\u003e\n  \u003cli\u003eSold as a pack of 10, enough to keep spares in the console and the shop\u003c\/li\u003e\n  \u003cli\u003eHella Marine fit-and-forget build, materials chosen to handle marine vibration, heat, and moisture\u003c\/li\u003e\n\u003c\/ul\u003e\n\n\u003cdiv class=\"nvn-trust\"\u003e\n  \u003ch2\u003eWhy Buy from NVN Marine\u003c\/h2\u003e\n  \u003cul\u003e\n    \u003cli\u003eAuthorized Hella Marine reseller, full manufacturer warranty\u003c\/li\u003e\n    \u003cli\u003eNMEA member and ABYC certified, advice from real boat techs\u003c\/li\u003e\n    \u003cli\u003eSame-day shipping before 3 PM ET on in-stock items\u003c\/li\u003e\n    \u003cli\u003eNY headquarters and Fort Lauderdale flagship retail store\u003c\/li\u003e\n  \u003c\/ul\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eFrequently Asked Questions\u003c\/h2\u003e\n\u003cdiv class=\"nvn-faq\"\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs this a 12-volt or 24-volt bulb?\u003c\/summary\u003e\n    \u003cp\u003eIt's a 24-volt bulb. It's meant for larger vessels, commercial boats, and rigs running a 24V system. If your boat is wired 12V, this isn't the right part. Put a 24V bulb on a 12V circuit and it stays dim.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eHow many bulbs come in the pack?\u003c\/summary\u003e\n    \u003cp\u003eTen. You get a full pack of 10 Hella Marine 7537 bulbs, which is enough to keep spares on hand since rear bulbs rarely go one at a time.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat does the 21\/5W rating mean?\u003c\/summary\u003e\n    \u003cp\u003eIt's a dual-filament bulb. The 21-watt filament is the bright element for the stop light or turn signal, and the 5-watt filament is the dimmer element for the running or tail light.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat base does it use?\u003c\/summary\u003e\n    \u003cp\u003eA BAY15d double-contact bayonet base. The two pins are offset so the bulb only drops in one way, keeping the bright and dim filaments on their correct circuits.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat shape and size is the glass?\u003c\/summary\u003e\n    \u003cp\u003eIt's an S8 envelope, the familiar straight-sided clear glass about an inch across that fits standard combination tail-light housings.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWhat is this bulb used for?\u003c\/summary\u003e\n    \u003cp\u003eStop, tail, and turn signal duty in rear combination lamps on 24-volt boats and heavy rigs. The clear glass works behind a red or amber lens.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eWill it fit a single-contact bayonet socket?\u003c\/summary\u003e\n    \u003cp\u003eNo. This is a double-contact BAY15d base with offset pins. It won't seat in a single-contact BA15s socket, so confirm your housing takes a dual-filament BAY15d bulb before ordering.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs it a replacement for a 1157 or 1034 style bulb?\u003c\/summary\u003e\n    \u003cp\u003eIt uses the same BAY15d base and 21\/5W dual-filament format as a standard 1157 or 1034 bulb, but it's rated for 24 volts rather than 12. Match the voltage of your system.\u003c\/p\u003e\n  \u003c\/details\u003e\n  \u003cdetails\u003e\n    \u003csummary\u003eIs the glass clear or colored?\u003c\/summary\u003e\n    \u003cp\u003eClear. The lens in your light housing provides the color, so the same clear bulb can serve red stop\/tail and amber turn-signal positions.\u003c\/p\u003e\n  \u003c\/details\u003e\n\u003c\/div\u003e\n\n\u003ch2\u003eTechnical Specifications\u003c\/h2\u003e\n\u003ctable class=\"nvn-specs\"\u003e\n  \u003ctbody\u003e\n    \u003ctr\u003e\n\u003cth\u003eTitle\u003c\/th\u003e\n\u003ctd\u003eHella Marine 7537 Halogen Stop\/Tail Bulb, 24V 21\/5W, BAY15d, 10-Pack\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eBrand\u003c\/th\u003e\n\u003ctd\u003eHella Marine\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eManufacturer Part Number\u003c\/th\u003e\n\u003ctd\u003e7537\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eUPC\u003c\/th\u003e\n\u003ctd\u003e760687145097\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eBulb Type\u003c\/th\u003e\n\u003ctd\u003eHalogen\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eLens Color\u003c\/th\u003e\n\u003ctd\u003eClear\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eQuantity\u003c\/th\u003e\n\u003ctd\u003ePack of 10\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eVoltage\u003c\/th\u003e\n\u003ctd\u003e24 Volt\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eWattage\u003c\/th\u003e\n\u003ctd\u003e21\/5 Watt\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eBase\u003c\/th\u003e\n\u003ctd\u003eBAY15d\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eBulb Shape\u003c\/th\u003e\n\u003ctd\u003eS8\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eFilament Configuration\u003c\/th\u003e\n\u003ctd\u003eDual filament\u003c\/td\u003e\n\u003c\/tr\u003e\n    \u003ctr\u003e\n\u003cth\u003eTypical Application\u003c\/th\u003e\n\u003ctd\u003eStop \/ Tail \/ Turn signal\u003c\/td\u003e\n\u003c\/tr\u003e\n  \u003c\/tbody\u003e\n\u003c\/table\u003e\n\n\u003cscript type=\"application\/ld+json\"\u003e\n{\n    \"@context\": \"https:\/\/schema.org\",\n    \"@type\": \"FAQPage\",\n    \"mainEntity\": [\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is this a 12-volt or 24-volt bulb?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It's a 24-volt bulb. It's meant for larger vessels, commercial boats, and rigs running a 24V system. If your boat is wired 12V, this isn't the right part. Put a 24V bulb on a 12V circuit and it stays dim.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"How many bulbs come in the pack?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Ten. You get a full pack of 10 Hella Marine 7537 bulbs, which is enough to keep spares on hand since rear bulbs rarely go one at a time.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What does the 21\/5W rating mean?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It's a dual-filament bulb. The 21-watt filament is the bright element for the stop light or turn signal, and the 5-watt filament is the dimmer element for the running or tail light.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What base does it use?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"A BAY15d double-contact bayonet base. The two pins are offset so the bulb only drops in one way, keeping the bright and dim filaments on their correct circuits.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What shape and size is the glass?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It's an S8 envelope, the familiar straight-sided clear glass about an inch across that fits standard combination tail-light housings.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"What is this bulb used for?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Stop, tail, and turn signal duty in rear combination lamps on 24-volt boats and heavy rigs. The clear glass works behind a red or amber lens.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Will it fit a single-contact bayonet socket?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"No. This is a double-contact BAY15d base with offset pins. It won't seat in a single-contact BA15s socket, so confirm your housing takes a dual-filament BAY15d bulb before ordering.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is it a replacement for a 1157 or 1034 style bulb?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"It uses the same BAY15d base and 21\/5W dual-filament format as a standard 1157 or 1034 bulb, but it's rated for 24 volts rather than 12. Match the voltage of your system.\"\n            }\n        },\n        {\n            \"@type\": \"Question\",\n            \"name\": \"Is the glass clear or colored?\",\n            \"acceptedAnswer\": {\n                \"@type\": \"Answer\",\n                \"text\": \"Clear. The lens in your light housing provides the color, so the same clear bulb can serve red stop\/tail and amber turn-signal positions.\"\n            }\n        }\n    ]\n}\n\u003c\/script\u003e\n","brand":"Hella Marine","offers":[{"title":"Default Title","offer_id":67601971478621,"sku":"2011361","price":3.99,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0299\/7266\/0317\/files\/ImageServerAPI_7f174040-ee5d-41d8-ae4c-5febd3540d41.jpg?v=1791028839","url":"https:\/\/nvnmarine.com\/products\/hella-marine-7537-24v-21-5w-bay15d-bulb-10-pack","provider":"NVN Marine","version":"1.0","type":"link"}