Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number IRS-021 found under Insulation Sleeving by Bae Systems. The National Stock Number assigned to this part is 5970121673501, 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 IRS-021.