Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 4056 (MODEL CB-200 found under Coupler Drawbar Ball Socket by Unique Functional Products. The National Stock Number assigned to this part is 2540016233004, and the Federal Supply Class is 2540 Vehicular Furniture And Accessories. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 4056 (MODEL CB-200.