Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number DU500020048 ITEM 4 found under Valve Flow Control by Fmc Technologies Inc. The National Stock Number assigned to this part is 4820016722004, 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 DU500020048 ITEM 4.