The DLR-2502 Rail from Desmond is a 250mm Arca-Type compatible plate that is ideal for balancing long lenses or shooting macro photography. Precision scales on the sides of the rail and the clamp allow for micro adjustments. The lens mount screws are in a sliding slot so they can be adjusted to fit different lenses. Two 1/4"-20 hex screws, two safety screws, and two hex keys are included for mounting your camera to the plate.