The Promatic Compact R is a 35mm SLR made by Petri for Photographic Research Organization Inc. and released in 1977. There are identical models named Petri MF-1 and Petri MF-T 1000, both made by Kuribayashi (Petri). The only difference between the models is the badges on the prism compartment and body. The camera uses an M42 mount for the lens. It features shutter speeds from 1 second to 1/1000 of a second with B and a self-timer. It also has flash sync at 1/60 of a second, and a removable hot shoe is mounted via the X-sync connector located on top of the prism area. This idea is similar to the Olympus OM SLR cameras. The meter is Cds based and was powered by PX675 mercury battery no longer available but a replacement is an A76 Alkaline battery. The light meter can be seen through the viewfinder and is activated with the shutter button halfway. This camera came with a Promatic 50mm lens and lens cap. It also has a single action right thumb film advance lever, fold down rewind crank (that when pulled up releases the back cover), a frame counter, and can use ASA 25 to 1600 films.