Ball at the bottom of the knob of the magic arm is designed with a anti-slip rubber ring to increase friction and help to lock the equipment tighter. The magic arm has an anti-slip rubber cushion on the bottom of both ends to prevent scratches to the bottom of the LED light. The magic arm is made of aluminum alloy, solid with higher durability Three knobs control its direction separately, easy to mount, adjust and place. Standard 1 or 4inch screw on both ends of the magic arm is suitable for LED video Light, Microphone, Phone Holder, Super Clamp, and other accessories with 1 or 4inch screws hole. Colour:Black Material:Aluminum Alloy type: Three Sections Package Contents: 1 x Magic Arm Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.