Hollow shaft nut drive, used for long bolts, studs or threaded rods, which reduces the time to tighten the fastener on the threaded rod by hand, and simplifies overhead fastening application operation Hollow shaft allows long bolts and threaded rods to pass through in tightening applications, while increased sleeve length allows better contact with nuts at difficult-to-reach high places on the ceiling or pipes. Hex nut inner hex nut diameter is about 9/16 inches (suitable for corresponding size hex nuts), the set contains about 6 inches, 8 inches and 10 inches (can accommodate bolt length) hollow sleeves; you can choose the right sleeve according to your threaded rod length 1/4 inch Hexagonal quick connection is directly used with impact drill and drill bit, automatic tightening, and fixed rubber ring Smooth, loose hollow socket inner wall prevents shaft bites and damages threads, simplifies your work while protecting your threaded rod Color: As Shown Material: Metal Package Contents: 3 pcs nut driver Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.