The convex mirror design allows, with no annoying rotation, to quickly see what is going on behind you, and by making small hand movements - also from the side, above and below you. This significantly increases the frequency of contact with your dive buddies. It can also be used to check your equipment during the dive, search for a boat without turning the head up to look at the surface, check the area behind you when entering the water and when swimming backwards to the shore or boat after the dive.