Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 638-0003 found under Lamp Incandescent by Robert H Wager Companyinc. The National Stock Number assigned to this part is 6240004856012, 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 638-0003.