Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number D40-0003 ITEM 5 found under Seat Valve by Dante Valve Company Inc. The National Stock Number assigned to this part is 4820016320399, 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 D40-0003 ITEM 5.