Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number C121B found under Track Shoe Vehicular by Lempco Products Inc. The National Stock Number assigned to this part is 2530001483491, and the Federal Supply Class is 2530 Vehicular Brake Steering Axle Wheel And Track Components. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like C121B.