Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 8S4581 found under Cylinder Head Compressor by Caterpillar Inc. The National Stock Number assigned to this part is 4310000048264, 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 8S4581.