Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 1S9875 found under Ring Set Piston by Caterpillar Inc. The National Stock Number assigned to this part is 4310000048265, and the Federal Supply Class is 4310 Compressors And Vacuum Pumps. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 1S9875.