CamDive Red Diving Filter for MEIKON iPhone waterproof cases 32mm This Red Diving filter is a wet accessory and must be attached underwater!Constructed using tough optically correct acrylic Enhances contrast and improves the color of blue water to give your subject a rich, natural tone In shallow depths, this filter can serve as an attractive alternative to artificial light sources 32mm threaded filter.Attachment String included Best Suited for Depths of 15-70 feet/4.5-12meters