Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number 21 19743 1 4 TU found under Plastic Tubing by Treadwell Corporation. The National Stock Number assigned to this part is 4710008635967, and the Federal Supply Class is 4710 Pipe Tube And Rigid Tubing. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like 21 19743 1 4 TU.