YINETTECH Shutter Lens Retaining Ring ID 38.4mm OD 46.4mm Thread Compatible with Fujinon Compatible with Copal #1

["Shutter lens retaining ring compatibility: compatible with Copal, compatible with Compur1, compatible with Prontor #1 size 1 shutters for fastening to lens boards on view, field, and studio cameras, ensuring stable seating during setup.","Lens board mounting ring: inner thread diameter 38.4 mm and outer diameter 46.4 mm fit boards drilled to spec, clamping a size 1 shutter evenly so the optical axis stays aligned for accurate focusing and controlled camera movements.","Photography repair and build use: replace missing retaining nuts, support DIY large format conversions, mount shutters to new boards, and keep classic cameras operational for coursework, studio upkeep, and field assignments with consistent results.","Material and design: metal alloy body with smooth threads for steady tightening; low profile form sits within common recesses and avoids interference with bellows or the front standard when adjusting rise, shift, tilt, or swing on large format setups.","Installation guidance: verify your lens board opening and shutter size 1 standard before purchase; hand tighten or use a spanning tool; ideal for home bench work, studio maintenance routines, and travel kits where quick service is needed."]