AP Compact 1 film developing tank is suitable for processing one roll of 35 mm film. It comes with one automatic reel that can be set for 35 mm as well as 127 and 120/220/620 roll film sizes, so it can be used for these film sizes in a larger tank. A small rod is included which allows you to rotate the film reels during development. The developing tank is sealed with an O-Ring and closes tightly.