Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 39E1-4 found under Cock Plug by Imperial Inc. The National Stock Number assigned to this part is 4820002771765, and the Federal Supply Class is 4820 Valves Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 39E1-4.