Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 661-D found under Bearing Stem by Duracell Inc. The National Stock Number assigned to this part is 3120011721631, and the Federal Supply Class is 3120 Bearings Plain Unmounted. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 661-D.