Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number X3991 found under Bearing Assembly by Haldex Inc. The National Stock Number assigned to this part is 3110010213538, and the Federal Supply Class is 3110 Bearings Antifriction Unmounted. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like X3991.