The Metabones MB_EF-E-BT4 EF to E Mount T Smart Adapter Mark IV is a cutting-edge, precision-engineered lens adapter that enables users to mount Canon EF lenses on Sony E-mount cameras with full electronic integration. This smart adapter is designed for photographers and videographers who wish to retain the advanced features of their Canon lenses while taking advantage of Sony's renowned E-mount system. The Mark IV version offers improved performance, enhanced compatibility, and a host of smart features to bridge the gap between two of the most powerful camera systems on the market.