PAR 36 Sealed-Beams
PAR36 bulbs (also known as tractor bulbs) are sealed-beam type bulbs similar to old-style car headlamps. They are normally used in spreader lights, deck lights, utility lights, tractor headlamps, motorcycle auxiliary lights, etc.
They are 4-3/8" in diameter with terminals as shown in the above picture. Marinebeam carries LED replacements for these PAR36 in several different outputs