Thank you for selecting Aerospace Aviation360 as your go-to distributor of part number TMXK4 found under Extension Socket Wrench by Snap On Holdings Gmbh. The National Stock Number assigned to this part is 5120001070055, 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 TMXK4.