1. High transparency, high color reproduction, more exciting photos. Waterproof and scratch resistant, effectively protecting the lens. 2. Choose professional optical glass lens and excellent lens grinding process to make the image clearer. 3. The multi-layered glass block prevents the harmful effects of UV rays and eliminates smog, correcting the chromatic aberration in the landscape photo. 4. Capture your best footages with the right color lens filter according to different condition: - Purple filter: Purple filter: The purple filter is color-corrected when shooting in green sea water with a depth of 5 to 25 meters. It is ideal for in freshwater lakes, fresh reservoirs or in salt water where because of green algae to take pictures. - Red filter: Red filter can be used around noon (sunlight direct water surface) in the water depth 10-20 meters, the main purpose is to reduce the red absorbed by water, effectively improve the blue phenomenon of underwater shooting, restore color balance, prevent shooting the image too blue or too green. - Red filter for the bluish environment, purple filter for the green environment. 5. Material: Aluminum alloy frame + glass lens. 6. Lightweight, high transmittance and low reflectance. 7. Note: The camera not not included.