The Polar Pro Aqua 3+ Red Filter Is designed for color correction while scuba diving in Blue and Tropical Water. The Filter simply pushes onto the Gopro Hero3+ waterproof housing. This filter allows the camera to capture vibrant tropical colors while diving from 4 to 25 meters. Why do you need a red filter while diving? The GoPro Hero3+ has an Auto White Balance, which improperly registers colors due to red light loss under water. This is why underwater videos often turn out very green or very blue. A red filter helps compensate for red light loss and allows the camera to properly record beautiful reef colors. Filter Slides quickly on and off of the Hero3+ Waterproof housing. Glass Lens for maximum scratch resistance. Working Depth: 10 to 80 Feet. Color correction for blue and tropical water.