Usage Tips:Features: brand and high quality High quality and compact, ultra-smooth finish. Durable, portable and lightweight. Made of aluminium. Allows infinite for focus. The aperture scale is adjustable. Manual operation, manual for focus, manual exposure. With high quality and durable performance. Specifications: Material: all metal Product model: M42 inner ring can be adjusted Applicable lens: M42 mount series lens Applicable cameras: for digital SLR cameras, some full-frame and film cameras, not suitable for use, there may be boarding phenomenon Product Features: Full manual control, manual for focus, for infinity for focus. Notes: When using the adapter ring for the first for time, please turn on the "Shutter release without lens" option in the body menu, otherwise it will not be recognized. Note: Please allow 0-1cm error due to manual measurement. pls make sure you do not mind before you bid. 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