Gitzo Series 2 Off Centre Ball Head Macro Tone to confirm charging has Tone to confirm charging has started The Circular PL filter removes reflection from water surfaces and glass windows while increasing contrast in landscape photography and darkening blue skies Friction control: By fine tuning the freedom of movement of the head friction control makes the head slower and more precise or faster and looser Double quick release safety system: The system consists of two pins one fixed and one manually operated by means of a button that prevent camera equipment from suddenly dropping out of the head when the quick release locking knob is released