Fits All Advanced Photo System Cameras. 4th Color layer. 400 Speed - All Occasions: Sunlight; Flash; Action; Low light. Cartridge fits Advanced Photo System Cameras only. This film is not for use in 35mm cameras. Light Sources: Daylight or electronic flash. Exposure Indicator: There are four symbols on the end of the cassette. The icons show the film's exposure status - 1. Circle (Unexposed). 2. Half Circle (Partially exposed). 3. X (Fully exposed but not processed). 4. Square (Processed). ISO 400/27.