The RB67 Professional was introduced in 1970 with a similar look to popular medium format SLR cameras like the Hasselblad V series, but was larger due to the larger 6×7 cm frame size. However, the RB67 differed visually from other medium format cameras of the time, which resemble very large 35mm cameras.[3]: 168  The RB67 is a modular camera system. This means lenses, viewfinders, ground glass, and film backs are interchangeable. There is no focal plane shutter in the RB67. The RB67's Sekor lenses have mechanical leaf shutters which are cocked on the body and triggered either from a threaded shutter release on the lens or from the body's shutter button. Focusing is performed with bellows on the body. Though the RB67 is a completely mechanical camera there are a variety of motorized film backs and automatic exposure finders that do require batteries.