Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number S52 1 25 9 found under Insulation Sleeving by The Boeing Company. The National Stock Number assigned to this part is 5970013328871, and the Federal Supply Class is 5970 Electrical Insulators And Insulating Materials. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like S52 1 25 9.