This is a red filter for your GoPro HERO 3's underwater housing. Red is the first wavelength of light to disappear underwater; this combined with the GoPro's auto white balance will leave you with video that is often too green or blue. This filter makes the color true again and is perfect for anyone looking for a solution to this issue. This filter will have the maximum effect from 10 to 75 feet. GoPro 3 filters work on GoPro 3 models: Black, Silver & White and GoPro 3+ models: Black and Silver. There are two ways to attach this filter. The best way is to use the mini star bit tool to remove the 10 screws from your housing and insert this filter between the actual lens front & the glass -or- you can simply attach the filter to the outside of the dive case with clear tape on the edges. Because the filter is larger than the opening, the tape will not be visible.