With the waterproof case you can perfectly use Yi 2/ Yi Lite/YI Discovery 4K 45m under water. Ideal for diving, snorkeling, surfing, wakeboarding and other water sport activities. Adopted with high light transmission PMMA material, will not affect your shooting effect. Anti-surf pressure design will not affect your movement and photographic effect. How to choose the filter color? Red Filter--Use for water depth of 10-20 meters, around noon (sunlight water) can be used red, the main purpose is to restore the water to be absorbed red and to leave you with natural colors. Light Red Filter--Reduces the green tones when filming in green water.This filter is great for lakes with algae or the green sea water. The Magenta filter is designed to pull the excess green color sout of the video leaving you with natural colors. Magenta Filter--This Filter will color correct your landscape . It usually used in green water or nightfall.(landscape Filter)