This kit includes a prop filter for every light condition. These prop filters fit all Flight Flix 52 filter adapters and GoPro safe cases. How it works? An HD camera image sensor is controlled by the amount of light it senses. In normal lighting conditions, the scanning frame rate of any CMOS HD camera causes distortion and odd lines in your video. The filter tricks the camera into sensing lower light which increases the exposure value of the camera. The brighter the conditions, the stronger the filter you will require. The ND2 is great for low light or cloudy days, the ND4 works well in most light conditions, and the ND 8 is for bright sunny days.