Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number C221318-4 found under Lamp Incandescent by Raytheon Company. The National Stock Number assigned to this part is 6240001561591, 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 C221318-4.