Originally Posted by
Onebyone
It is about 20 in long and enclosed in a housing. Like the under cabinet lights you can buy. All now have the three prong but the first ones had the two prongs It is a light strip of LED inside the housing. No glass bulb.
Likely those bulbs are 12V or 24V low voltage DC, and the fixture (light bar) itself has the AC to DC converter.
3 prong is likely 120VAC with the AC to DC converter built in to the bulb.
There should be markings on the bulbs to verify the voltage they work on (and possibly the base size/designator).