Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number HL-21023 ITEM 6 found under Gasket by Atlas Copco. The National Stock Number assigned to this part is 5330000906094, and the Federal Supply Class is 5330 Packing And Gasket Materials. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like HL-21023 ITEM 6.