Velbon QB-F51L Long Quick Release Plate Description. The Velbon QB-F51L Quick Release Plate is the long sliding quick release plate for the FHD-51Q Fluid Head. It features a 14-20 camera screw with an adjustment range of 4. 3 110mm. A quick release plate can be kept attached to the cameras base at all times & allows the user to quickly & easily attach or remove the camera from the tripod without having to waste time fumbling with the threaded mount