1. The main screw slot design cooperate clip on the positioning of the shaft make the clamping piece always stay in one direction 2. PU gasket can rise to increase friction force and protect the action of force 3. At the end of the screw shaft with a diameter of 16 mm of universal joint which can be used to install lamps and lanterns or all kinds of film in the attachment. 4. Have the same 16 mm and talons multi-function mother can be used with a lot of accessories. 5. According to the principle of human body mechanics design of handle easy and comfortable to use.