Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number R01-03G-1FFX found under Parts Kit Check Valve by W And O Supply Inc. The National Stock Number assigned to this part is 4820015687151, 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 R01-03G-1FFX.