The P-CLAMP allows you to mount most smartphones to your Beholder EC1 or MS-PRO gimbals. It is made out of high quality machined aluminum for durability and looks. It features rubber pads on the top and bottom to help keep your phone scratch free. The clamp uses a tightening knob to keep your phone securely in place. The max width of the P-CLAMP is 3.57 in.