The Canon Mount Adapter EF-EOS R lets you connect your existing EF or EF-S lens to your EOS R system camera while maintaining the same levels of performance and functionality as on your DSLR. It’s perfect for photographers who already have a number of EF lenses. Canon EOS R adapters are built for tough environments and are weather-sealed against dust and moisture. Finally, as the adapter is lightweight –approximately 110g – it means that it doesn't add much weight to your lens.