Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number TK156-4056 ITEM 11-5 found under Lens Light by Electric Boat Corporation. The National Stock Number assigned to this part is 6220013641675, and the Federal Supply Class is 6220 Electric Vehicular Lights And Fixtures. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like TK156-4056 ITEM 11-5.