Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 6670-0021 found under Spacer Sleeve by Accessories For Electronics Inc. The National Stock Number assigned to this part is 5365013340598, and the Federal Supply Class is 5365 Bushings Rings Shims And Spacers. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 6670-0021.