The Sirui TY-350 Telephoto Lens Support Quick Release Plate is specifically designed to provide a stable and steady platform for your camera body and telephoto lens. The quick release plates have single contact point which make these unstable but Ty 350 plate provide the ultimate in support and stability with dual screws that attach to the lens foot, and an adjustable vertical support for the camera body. This dual contact point plate takes the weight of the camera off the lens foot and provides an additional contact point, adding stability. It features three long channels that lets precisely center the weight of the camera and lens over the head, ensuring your rig isn’t front or rear heavy, adding even more stability.The channels are 19 inches (482mm) long and have rubber grips that provide a slip-free surface for your lens’ foot. There are also 2 screws that can fit into the bottom of the lens foot to guarantee exacting lens alignment and security. Each platform has a ¼” and 3/8″ screw that can be positioned in any of the 3 slots. To change position on the VH-350, simply remove the rubber grommet, slide out the screw and place it into another slot. For the YT-350, unscrew the screw and place it in the desired slot. Fast, easy and perfect for any size lens. This is the first contact point on the plate.The second contact point is on the end of the plate. There is a vertically adjustable support plate that is connected to an Arca-compatible Quick Release Platform. A Sirui Quick Release Plate attaches to your camera body. The vertical plate can be moved up or down to precisely match the position of your camera when it is attached to your lens. If you need to switch the body from vertical to horizontal position (the lens has a collar that lets you rotate the barrel) simply remove the QR plate and attach an Arca-compatible “L” bracket (optional) onto your camera. This will now allow you to switch camera position and still be locked into the QR platform. In addition to