Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number W55 1IN found under Valve Gate by The Walworth Company. The National Stock Number assigned to this part is 4820014639102, 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 W55 1IN.