1Versatility: The M42 to C CS mount adapter ring is a multipurpose tool, widely used for changing M42 lens or focusing barrel to C CS port. It can provides valuable flexibility and variation in your photography. 2Aluminum Alloy Material: M42 to C CS mount adapter ring is made of aluminum alloy, high strength, sturdy, strong, wearproof, beautiful workmanship, rust resistant for long lasting use. 3Special Use: The adapter ring is most commonly used for macro and astronomical photography. It opens up a whole new world of photographic opportunities, enabling you to capture highly detailed close ups. 4Lightweight and Portable: Compact and lightweight design makes it easy to install and use, the adapter ring is utterly suitable for travelling astrophotographers, enabling you to capture beautiful images wherever you go. 5Accurate Craftsmanship: The C CS mount lens adapter ring features accuracy machining and anti reflective inner walls to prevent stray light for optimized imaging quality. 1 xM42 to C CS Mount Adapter Ring