Patuo Super Clamp Large Size w/ 1/4 Inches & 3/8 Inches Threaded Hole for Camera,Umbrellas,Shelves,Cross Bars, Lighting, Photo Accessories This articulating magic friction arm is universal that can fix onto any shaped body like cameras, lights, umbrellas, hooks, shelves, plate glass, cross bars,etc. Super Clamp Comes with 1/4"-20 and 3/8"-16 thread. Non-slip rubbers on the inner side provide strength and stability. Maximum opening diameter: 1.97inch/5cm. Strong construction, Material: Lightweight Aluminum Alloy and stainless steel. Net weight: 0.13kg.