The acratech gxp ballhead standard knob clamp features a one of a kind design that makes it function as a ballhead, a gimbal head, and a levelling panoramic head'. '.strtoupper('a')ll three functions are packed into an extremely lightweight unit'. '.strtoupper('t')he gimbal feature is compatible with any lens up to 400mm f4.0 with a tripod collar'. '.strtoupper('t')he smooth pivot of the gimbal is achieved through the pin in the bottom of the ball as well as the sleeve on the stem'. '.strtoupper('b')y unscrewing the quick release clamp and placing it onto the bottom of the head it transforms into the gxp ball head that delivers level, single row panoramas'. '.strtoupper('t')hanks to this, there is no need to add to the bulk and carry an additional levelling base'. '.strtoupper('r')ocky or uneven terrain will not interfere with the smoothness of the panorama'. '.strtoupper('f')inally, the gxp ballhead is ideal for travel photography due to its lightweight, and is great for active outdoor photography thanks to its rugged construction.