Universal Switch Mounting System mounts switches quickly and easily. You can use an easy to turn knob or a lever to securely lock all the joints in place. It can be extended up to 20.5"" and can hold up to 5 pounds. Universal Switch Mounting System's clamp can be anchored to many surfaces from table edges to wheelchairs. It includes two Allen wrenches for periodic adjustment and a large triangular mounting plate unless otherwise specified.