Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number GM25 18 found under Valve Check by Assembly And Test Worldwide Inc. The National Stock Number assigned to this part is 4820012381653, 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 GM25 18.