For Quick Release use and allow for sliding back and fro for quick release plate with 1 or 4inch standard screw for camera Dual 15mm rod support system included Clamp base: compatible with for 577 or 501 or 504 or 701 tripod The HDRIG Baseplate kit is used for mounting cameras on the tripod, shoulder rig and cage kit. It comes with a 15mm dual rods system and adjustable lens support. for base plate designed to add quick release capability for DSLR cameras or cages, it also allows the camera to slide back and fro on the mounting plate. An integrated dual 15mm rod system for follow focus, lens support, matte box and other accessories to be attached. There are 1 or 4inch and 3 or 8inch thread holes on the bottom of the for baseplate and the rod clamp, which makes it possible to be directly attached to a tripod or or other devices which helps provide the flexibility to various purposes. Lens Support Bracket: Y shape with rubber pads on the top for eliminating lens vibration. It is adjustable in height (max 60mm) and fits lens diameter range from 50mm to 140mm. The standard 15mm diameter 60mm spacing holes are compatible with any 15mm rail rigs. 20cm Long Rod (2 pieces) made of HQ aluminum alloy, allows you to easy mount capability for follow focus, matte box and more. Colour:As Shown Material:Aluminum Alloy Package Contents: 1 x Quick release plate base Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is 1-3cm.