Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 52U137 found under Insulation Blanketelectrical by United Technologies Corporation. The National Stock Number assigned to this part is 5970016894345, 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 52U137.