Description: 55x400mm Telephoto Lens Tripod Quick Release Plate Rail Slider Mount 1/4" & 3/8". For Fotopro 501PL/500AH/502/701/577, Benro S4 S6 S8, etc. Suitable for 600mm, 800mm and 650-1300mm telephoto lens. Foldable platform, compact design, for more combination options. 400mm length, 50mm width, with spirit level & knob to adjust horizontal, vertical, multiple angles, to meet your photography needs. Made from CNC aluminum alloy, hard anodized surface, light weight and durable. Specification: Material: Aluminum Alloy Size: 48x5.5 cm/18.9x2.2 inch Package Includes: 1x Quick Release Plate 1x Wrench Note: The mounting hole between lens and camera need to be larger than 75mm, to install properly