Ball joints provide unfettered multi-directional movement. Clamps two 25 mm ball arms together, crafted of corrosion-resistant aluminium. The Clamp is made of machined lightweight aluminum alloy and weighs only 55g/1.9oz. The thumbscrew type gives easy clamping and unclamping. Not only allowing 360 degrees free oscillating movement between attached arm system, also gives approx. 80 ° movement along an extended line of attached arm.