Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number A4XR found under Socket Socket Wrench by Nmtcinc. The National Stock Number assigned to this part is 5120013682018, and the Federal Supply Class is 5120 Hand Tools Nonedged Nonpowered. Our website is owned and operated by ASAP Semiconductor, a leading distributor of aviation and aerospace part numbers like A4XR.