The Light Source Mini Clamp, Aluminum Finish Specifications: Minimum Size: 3/8" pipe, .675" OD Maximum Size: 1.5" pipe, 1.9"OD, 2" OD Truss Tube Safe Vertical Working Load: 150 lb 70kg Hardware: Pipe bolt is a steel 3/8"-16 TPI x 2" stud with a Black Plastic Knob, Yoke bolt is a 3/8"-16 TPI x 3/4" long, Belleville Washer. Diminsions: 4" tall x 2-3/4" wide x 7/8" thick Weight: 6oz