Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 6-1600WSS-M found under Valve Vent Check by Robert H Wager Companyinc. The National Stock Number assigned to this part is 4820015105802, 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 6-1600WSS-M.