This is Linear motion lead screw focusing or micro rail WITHOUT clamp. If you need clamp please look for Linear motion lead screw focusing or micro rail WITH clamp.
The bottom rail (5/8 thick) include Arca Swiss compatible dovetail that works with Arca Swiss type clamp while the slider is equipped with quick release clamp. Clamp can be oriented in 3 positional. It can not be set with knob on the same side as slider lock knob. Knobs will interference between each other. Camera to subject distance can be adjusted in fine increments . Lead screw delivers 1.06 mm of travel per full revolution. Fast positioning can be done by pressing slider release lever and slide the slider on top of the rail. After seting position slider can be lock in position with side lock. Works very nice as a nodal slide.
It is It is the best quick release system for tripods and monopods when combined with Arca style ball head and quick release clamps. International standard dove-tail rail, compatible with Arca-Swiss type quick release clamps