This 3d printed back allows you to shoot Instax Square film. It does not require any expensive battery. Just use the crank to manually eject the film. The modification is completely reversable, no damage is required. Easy manual release means no more worrying about the battery running out. The back contains a dark slide and is dialed perfectly into the film plane with zero light leakage. The back could also shoot instax mini. I have included a special frameline finder for instax mini camera. Thanks for viewing:)