Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 6R109-42 found under Valve Restrictor Check by Allen Aircraft Products Inc. The National Stock Number assigned to this part is 4820002276306, 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 6R109-42.