Rollei is known for its twin-lens reflex and development of Roliflex cameras, although the company branched out to include a range of products that include lenses, including slide projectors. They made several 35mm models, including the 350A slide projector that came out in 1974, and was marketed to two target groups; collectors of slide projectors and historical objects, and individuals seeking to continue to view 35mm slides in their period format.