The Cressi A1 Anti Fog Mask is crafted of silicone and a single tempered-glass lens. This mask is highly adaptable, with a double internal skirting along the top side for a more effective and guaranteed seal. The drain skirt also improves water explusion during mask clearance, whilst drastically minimizing water pooling. In typical Cressi fashion, the lenses themselved are inclined, meaning they have an inverted teardrop shape, to increase downward visibility. The Cressi A1 Anti Fog Mask is the perfect SCUBA diving tool when paired with its perfect match - the Epsilon SPE Dry Snorkel!