2 stars, only for the price and ease of use. The washers in question must be asked on the window of the plastic box which is not easy with the tab washers, camera lens is placed over hoping that all this remains in place. And do not position them if there is wind or you'll have lost 15 !!! For the filtering efficiency and rendering underwater videos, I can not talk about because I have not done the test. Yet to see the loss of light engendered these pellets, it seems that digital filters by software would be more effective, but check!
