Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4B8144 found under Bearing Sleeve by Pettibone Westrac. The National Stock Number assigned to this part is 3120003741197, 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 4B8144.