Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number R141-7 found under Valve Check by Koolant Koolers Inc. The National Stock Number assigned to this part is 4820015233634, 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 R141-7.