Description: 1. The filter is specially designed for , used for color correction when diving , suitable for tropical water system and blue water system; 2. The video or photo taken without the filter is too blue or too green.3. Use it between 3.5 meters and 25 meters, there is enough red light in the water above 5 meters, so no filter is needed.4. Some wavelengths of light cannot penetrate water bodies, so videos under water will cause problems with bamboo shootsFeature: 1. Convenient disassembly and assembly, the filter has a lanyard hole, which can be bound to prevent the loss of the rope and will not lose the filter;2. Light red filter, correct the color deviation, restore the blue color, suitable for diving;3. Red filter, restore the greenish color, suitable for in sea water;4. Purple filter, restore the blue color, suitable for fresh water .1. Red: red and smoke filters can be used around noon (direct sunlight on the water), the main purpose is to restore the red absorbed by water2. Purple mirror: specially designed for , used for color correction when mountain scenery, suitable for green sea water dusk system3. Light red, depending on the angle of the sceneSpecificationProduct size: 12.5x10.5x5cmSingle product weight: 32gWaterproof depth; 45-50mcolour: red + purpleMaterial: high-transparent PU material + tempered glassPackage Contents: 3 * Waterproof Case Lens Filters for Hero 9 BlackOnly the above package content, other products are not included.Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.