The Tether Tools Jerkstopper A Clamp clamps to a round or flat object to provide an anchor point and allow cable slack, preventing it from being pulled out while you’re shooting. Cable is routed through the Jerkstopper, which can be rotated on the clamp handle to change the routing orientation. It can be used with any cable with a diameter between 3.5mm and 8.5mm. Designed for pressure clamping with a quick installation and removal, the clamp features a non-reflective black finish. The tips are polyvinyl-coated to protect equipment from damage. The jaws open to a maximum of 1″ wide.