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 does a prop filter work? 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 any fast moving objects to move during the scanning motion (frame rate) of the camera. Our filter tricks the lens sensor into increasing the exposure value of the camera. The brighter the conditions, the stronger the filter you will require. This kit gives you a filter for every condition. 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.