The Canon Control Ring Mount Adapter EF-EOS R is a lens mount adapter designed for EOS R series users featuring an integrated customizable control ring. Seamlessly adapts EF and EF-S lenses to EOS R cameras for maximum lens compatibility Customizable control ring allows quick adjustment of aperture, ISO, shutter speed, or exposure compensation for faster workflow Maintains full autofocus and image stabilization functionality for reliable performance with adapted lenses Weather-resistant construction ensures dependable operation in challenging shooting environments All-metal lens mount delivers a secure, durable connection for professional use No optical elements preserve original lens image quality without introducing distortion or aberrations Compact and lightweight design makes it easy to carry and mount without adding bulk to your kit Gold-plated contacts support fast, accurate communication between lens and camera for enhanced responsiveness Supports in-camera lens corrections for vignetting, chromatic aberration, and distortion for superior image results Effortless plug-and-play installation lets you start shooting immediately, saving time on set or in the field