This XPRO Magnesium Ball Head from Manfrotto features an integrated Arca-type clamp and a MSQ6PL Quick Release Plate. Arca-type compatible quick release plates such as the MSQ6PL can be attached or removed from the Arca-type clamp located at the top of the ball-and-socket joint by tightening or loosening the clamp's locking knob. Within the recessed surface between the clamp's jaws is a retaining pin. This pin prevents an installed quick release plate from accidentally sliding off when the clamp is opened. The XPRO Magnesium Ball Head with MSQ6PL Quick Release Plate has a load capacity of 33.1 lb and can be attached to tripods or other support systems that feature a 3/8"-16 mount. By loosening this XPRO Magnesium Ball Head's primary locking knob, its ball-and-socket joint can be quickly swiveled, angled, fully tilted, or returned to its upright position. Toward the ball head's base is a secondary locking knob that controls the ability to rotate the head 360°. An additional knob opposite the secondary locking knob can be rotated to apply tension control to the ball-and-socket joint's movements. Cameras or accessories that are compatible with a 1/4"-20 mount can be connected to the MSQ6PL Quick Release Plate which measures 2.8 x 2.2 x 0.4".