Here's a special package deal on light bulbs to convert your M-series military tail lights, brake lights, turn signals, and marker lamps from 24 volts to 12 volts. The most common use is to convert a military trailer (M101, M105, M1101, or other) to be pulled by a civilian vehicle, but they are also usable when converting a military vehicle to a 12 volt electrical system overall. Note that when converting a vehicle like an M37, you'll also need to replace the headlights, turn signal mechanism, generator, voltage regulator, and starter, and either replace all the electrically-operated gauges or get a 12-24 voltage converter for them. This set only includes the light bulbs shown.

The 12V #1156 lamp replaces the 24V #1683 lamp and the #67 lamp replaces the #1251 lamp. for your M-series army truck. The set includes one box of 67s, which are the most common, and one box of 1156s, which are the bright brake light bulbs. The lamps, of course, will be packed in boxes, not shown in the photo. Each box contains 10 bulbs. Note that the 12 V conversion bulbs are not absolutely identical to the 24 V bulbs in terms of internal construction and precise brightness level, but they are the same physical size and so close to identical performance that there's no visible difference. They can also be used in the blackout lamp positions, if you want to maintain blackout functionality with your 12 V vehicle.

I also list the original 24/28 volt bulbs, individually or as sets.