iShoot All Metal Lens Collar Support Tripod Mount Ring IS-EOS-R-PRO for Canon EF-EOS R Mount Converter Lens Adapter Ring (Can Only be Used for EF-EOS R Basic Models, not for Models with Filters or Focusing Rings) Support Vertical Shoot, Bottom is ARCA Fit Quick Release Plate Feature Compatible with Tripod Head Clamp of 39mm ARCA-SWISS / RRS Fit Main Features: 1. The tripod mount ring is tailor-made for Canon EF-EOS R adapter ring, CAN only be used for EF-EOS R basic models, not for models with filters or focusing rings; relying on the switch and bayonet positioning, cannot rotate in the tripod ring; when shooting vertically, the EF-EOS R adapter ring needs to be taken out and reinstalled; 2. The edges and corners are polished, the inner wall is affixed with 3M plastic film, preventing the lens from scratches; the shortest inner diameter of the lens holder is about 73mm, the width of this contact surface is about 18mm; net weight is about 145g; 3. The tripod collar bottom is added 55mm long Arca fit quick release plate feature, can be used with 39mm Arca-swiss fit tripod ball head, panoramic head and clamp directly; more practical than lens collars without QR-Plate; also reserved 1/4" and 3/8" screw holes and stainless-steel anti-slip screws for fixing lens to tripod directly? Applicable to: Canon EF-EOS R Mount Converter Lens Adapter Ring (Can Only be Used for EF-EOS R Basic Models, not for Models with Filters or Focusing Rings, and Can't be used for other lenses) Package Includes: 1 x iShoot Tripod Mount Ring IS-EOS-R-PRO for Canon EF-EOS R Mount Converter (Note: The other items in the photos not listed here are for illustrating only, not included)