Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 660-4 found under Conveyor Acft Baggage Special by Stewart And Stevenson Services Inc. The National Stock Number assigned to this part is 3910013856322, and the Federal Supply Class is 3910 Conveyors. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 660-4.