Features: Brand new and high quality High quality and compact, with an ultra-smooth finish. Durable, portable, and lightweight. Made of aluminum. Allows for infinite focus. The aperture scale is adjustable. Manual operation, manual focus, manual exposure. With high quality and durable performance. Specifications: Material: All Metal Product Model: M42 inner ring adjustable Applicable Lens: M42 mount series lens Applicable Cameras: For digital SLR cameras, some full-frame and film cameras. Not suitable for use, may cause mounting issues. Product Features: Full manual control, manual focus, infinity focus. Notes: When using the adapter ring for the first time, please enable the "Release without lens" option in the body menu; otherwise, it will not be recognized. Note: Please allow 0-1 cm error due to manual measurement. Please ensure you don't mind before bidding. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you! Package Includes: 1pc x M42 Lens Adapter Ring