The semicircular spherical DOME pushes the water sur away, allowing the lens to have enough field of view, so that objects above and below the water can be photographed, giving you a great experience and taking great pictures. If you only use a simple camera to take pictures that are half underwater and half above the water, it is difficult to take good pictures, because the water blocks the perspective, underwater objects are distorted, and water magnify objects like a convex lens. Therefore, if you want to balance these things, you must use DOME PORT. The semicircular spherical DOME pushes the water sur away, allowing the lens to have enough field of view, so that objects above and below the water can be photographed, giving you a great experience and taking great pictures. Water magnify objects in the water like a convex lens. Direct shootingwill make objects in the water distorted and larger. Compared with objects on the water sur, the photos taken in this way are very inconsistent. Using DOME PORT can well coordinate underwater and sur objects, so that the photos taken are very normal, giving you a real world. Colour:Black Material:Plastic Package Contents: 1 * Fisheye Lens Cover Only the above package content, other products are not included. Note: Light reflection 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.