Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number D-WK-492-A43 ITEM 9 found under Valve Check by Walz And Krenzer Inc. The National Stock Number assigned to this part is 4820012578657, 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 D-WK-492-A43 ITEM 9.