Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 55505 104 found under Lamp Incandescent by Safe Flight Instrument Corporation. The National Stock Number assigned to this part is 6240015538634, and the Federal Supply Class is 6240 Electric Lamps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 55505 104.