TULEX IMPACT UNIVERSAL JOINT : Tulex Swivel Impact Joint is a coupler interposed between impact socket and the impact wrench. It is useful for tightening nuts located at difficult / angular positions, which cannot be reached with standard tools. These are available in 3/8" (9.5 mm), 1/2" (12.7 mm), 3/4" (19 mm) 1" (25.4 mm) and 1.1/2" (38.1 mm) square drives.