Nemin mask has a particular tapered structure. The dual integrated frame system joins the silicone skirt to the lens frame without major interruptions of the curvature continuity. The result is a mask with an extremely hydrodynamic shape and a significantly smaller size, with equal visibility. The field of view obtained is particularly wide, laterally and in the lower zone. The skirt, in the front part, has a structural silicone insert which increases the sealing ability of the mask and creates an exceptionally pleasant chromatic play.