Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 221374 found under Parts Kit Brake Chamber by Mack Trucks Inc. The National Stock Number assigned to this part is 2530004477667, 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 221374.