Magic Gripper Door Clamp This patented but simple effective British invention is very simple to set up and uses the weight of the product to clamp securely. With the new body shape, the new magic gripper is stronger and stable, and the anti-rock square feet make the magic grippers easier to control. Once adjusted to fit the product, it's ready to work the jaws will be in the open position until the door or product is placed into the jaws.