Neewer Aluminum Alloy DSLR Rail 15mm Rod Support Baseplate with 1/4" Screw Quick Release Plate for Follow Focus Mattebox DSLR Rig System The base plate is a aluminum alloy multi-functional standard rail system that can be used for mounting DSLR Follow Focus Rig This Rail System has a central Tripod Mounting plate that makes a perfect balance between the camera and the front mount accessories (35mm Adapter/Matte box/Follow Focus) Plate With the 1/4" screw, compatible with most DSLR/DVR The Tripod Mounting plate with the 1/4" and 3/8" screws threads, compatible with many support and tripods Note: 15mm Rail Rod Support ONLY, other accessories not included