Also Known As: Change-Over, Reel Change, Reel Change Marks, Cigarette Burns. Most completed movies consist of more than one reel, and thus for an uninterrupted screening, at least two projectors must be used. Towards the end of a reel, one or more frames may include a small circle in one of the corners. These are signals to the projectionist that the current reel is approaching the end, and he or she should be ready to start the next projector, which should have the next reel prepared for projection. Also, many theatres have switched to a platter system which allows the entire film to be spliced together and put on a large platter. The film is fed through the centre of the reel (unwinding from the inside out), then into the projector, and then back onto another platter. This process allows the film to be show back-to-back without having to rewind it.