The Snap-on 3/8" Drive 3-1/8" T40 Bit Socket, No. S6340E, is the tool for servicing injectors on the Ford 6.0L Power Stroke Diesel Engine.This tool allows users to remove and install hold-down fasteners. According to the manufacturer, a regular length T40 bit socket is too short and a long T40 bit socket is too long when used with a ratchet or torque wrench and will not fit the application. The S6340E has a 3-1/8" length and is specially made for the removal and reassembly of Ford Power Stroke 6.0L diesel injectors.