Hella Marine 2845 24V 5W Wedge Bulb, W2.1x9.5d Base

This is the Hella Marine 2845, a 24-volt, 5-watt miniature replacement bulb with a W2.1x9.5d capless wedge base. It's the little filament lamp that lives behind your gauges, inside a courtesy light, or in a small panel fixture. When one burns out, this is the exact spec you drop back in, no guesswork and no adapters.

The thing to get right first is voltage. This bulb is rated 24 volt. Most recreational boats run 12-volt house systems, but plenty of larger cruisers, commercial vessels, and work boats run 24 volt instead. If your electrical system is 24V, this is your match. Run a 12-volt bulb on a 24-volt circuit and it burns out fast. Run this 24-volt bulb on a 12-volt circuit and you'll get a dim, yellow glow that never comes up to full brightness. Match the voltage to your system and you're set.

The base is a W2.1x9.5d capless wedge. No pins, no bayonet, no screw thread. The glass pinch seats directly into the socket. The envelope is a T3, the industry T-3.25 miniature shape, so it's a compact bulb that fits the tight housings behind instrument clusters and indicator lamps. That 5-watt filament puts out a warm, familiar glow, the kind that's been lighting helms and panels for decades.

Not sure if this is your bulb? Check three things. Look at the markings on the old lamp, look at the base, and confirm your system voltage. The base should be a smooth two-wire wedge, not a metal bayonet cap and not a screw thread. If all three line up at 24 volt, 5 watt, and W2.1x9.5d, you've got the right part. The trade number here is 2845, a common designation, so it's easy to cross-check against whatever came out of the socket.

Swapping a wedge bulb is about as easy as it gets. Kill power to the circuit first. Then grip the old bulb and pull it straight out of the socket, no twisting needed. Line the new one up and push it straight in until it seats. That's it. Because there's no bayonet pin to align and no thread to cross, you can do the whole job by feel in a cramped console without dropping hardware down into the bilge.

Where does a bulb like this live? Instrument and gauge backlighting. Courtesy and step lights. Small indicator lamps on a switch panel. A chart light at the nav station. Anywhere a boat builder specced a 24-volt, 5-watt wedge lamp, this one drops right in. It's a workhorse part, not a showpiece, and that's exactly the point. You want it to light up every time you flip the switch and otherwise stay out of your way.

Hella Marine builds to a fit-and-forget standard, and that philosophy matters even on a part this small. Decades of marine lamp experience go into the glass, the filament, and the seal. Out on the water a bulb takes vibration, salt humidity, and temperature swings that a bulb in a house never sees. Quality materials and honest construction are what keep it lit season after season instead of leaving you with a dark gauge halfway through the run.

One last detail worth knowing. This listing is for a single bulb, not a multi-pack, and it's a filament bulb rather than an LED, so it's a true like-for-like replacement for the original lamp your boat shipped with. Here's our advice. Keep a couple aboard. Panel and courtesy bulbs always seem to go at night, offshore, when the chandlery is closed. Having the right 24-volt, 5-watt wedge bulb sitting in your spares kit turns a dark gauge into a 30-second fix.