SMALLRIG Super Clamp w/1/4 and 3/8 Thread for Cameras, Lights, Umbrellas, Hooks, Shelves, Plate Glass, Cross Bars, etc - 735 The clamp is made of Aluminum Alloy. The metal makes it sturdier and stronger. Versatility: Mounts onto anything like cameras, lights, umbrellas, hooks, shelves, plate glass, cross bars, even other Super Clamps. It's up to your imagination & inventive ideas. The jaw opens to max about 2.3" (58mm), and minimum 15mm rods. You can clip it on anything less than 58mm thick an more than 15mm. Non-slip and protection: The rubber pads on the metal clamp make it not easy to slide down and could protect your item from scratch. 1/4" & 3/8" thread: The 1/4" & 3/8" on the back of the clamp. You can mount other accessories via the 1/4" or 3/8" thread. Such as SmallRig Monitor bracket 2070.