The 7 inch Tether Tools Rock Solid Articulating Arm can hold lights, monitors, viewfinders, mics and other accessories that can be mounted on 1/4 inch screws, and it connects to a camera to attach these accessories for use with the camera. A hot shoe adapter is included for connecting to a camera. The Arm can also hold tablets and smart-phones, per the addition of the appropriate Tether Tools accessory. To hold a smart-phone, you'll need to add a SmartClip Universal Mount. To hold a tablet, you'll need a combination of a Connect Lite and a Wallee Case for iPad & Galaxy (iPad and Galaxy are the only tablets supported). Many other Tether Tools accessories are available for different uses with the Arm. A notable one is a Mini ProClamp, which can attach the Arm to various round surfaces, like video rig rods, tripod legs, and stands.A single knob loosens and tightens all the ball joints simultaneously. The screw at each end is a 1/4 inch screw. The Arm reaches a length of 7 inch when fully extended and supports a maximum of 4.5 lbs of weight.