This Pro Lens Adapter from Fotodiox enables the use of your Mamiya RB67 lenses on Sony A mount SLR and DSLR cameras. It features a durable brass construction with stainless steel finish, a leaf spring ensures a secure connection between the lens and adapter, and its design also maintains infinity focus. Due to the unique design of Mamiya RB lenses, this adapter has a focusing helicoid to enable smooth, controlled manual focus operation. Additionally, a tripod mount is featured to help offset the weight of the medium format lenses for more balanced and stable shooting.