The Stoboframe Metz Mount 4 is for those who prefer to use Metz's quick-release system on a Stroboframe mounts. All mounts have a machined tongue that slides directly into the Metz quick-release coupling. It has a locating pin ensures that it will stay snugly and won't twist on the bracket. Stroboframe makes mounts for every type of flash unit. The Metz Mount 4 is specifically designed for use with the Pro-RL and Pro-SQ. A 1/4"-20 knob or screw is included with all brackets to attach to any of the flash mounts. This knob also functions to attach flash units with 1/4"-20 sockets or dedicated TTL cords.