Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 2S5243PT55-56 found under Stem And Poppet by Ruggles Klingemann Mfg Co. The National Stock Number assigned to this part is 4810004313976, and the Federal Supply Class is 4810 Valves Powered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 2S5243PT55-56.