Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 21052 found under Insulator Spreader by Engility Corporation. The National Stock Number assigned to this part is 5970013885353, 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 21052.