We have designed this clamp to be able to mount on 1.75" diameter tubing and tighten up with two 3/8-16 bolts. This clamp works great for mounting roof racks and light bars at any angle. Simply install one hyme joint with 1/2-20 threads in the end and clamp other end around your tubing and tighten the two 3/8-16 bolts. This clamp has unlimited possibilities.