Robinson Rib Clamp Base: This base clamp fits the wind screen rib channel on any Robinson R22, R44, R66 Helicopter or any 3/4" tubing such as on Super Cub or Husky cockpit airframe tubing. This clamp can be easily tightened by hand making it a FAA friendly temporary mounting device. The thumb screw head also has a hex drive allowing you to use the included hex wrench tool if needed. This Clamp Base has a 1/4-20" socket allowing you to attach your own mounts or any RAM ball mount.