Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number M1990C found under Ball Bearing by Marine And Industrial Transmissions Lt. The National Stock Number assigned to this part is 3110010115006, 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 M1990C.