The Q=MOUNT XD Cross Clamp from NOVOFLEX is an Arca-Swiss type quick release clamp that offers 90º cross clamping capability. In conjunction with double-sided rails, it can be used in numerous applications, including macro and stereo photography. It has a double-sided coupling. One knurled metal thumb screw tightens/loosens the clamp while a second opens the bottom profile to fit on a rack or other compatible gear. Two safety stops prevent equipment from falling (no longer includes bubble level). With to its bottom clamp, the Q=Mount XD fits on the Castel-XQ II Focusing Rack for adjustable camera movements with Castel T/S bellows or other similar device.