This is the Riffe Nekton Mask Spearfishing Freediving Mask - Lens Options Features: Heat treated silicone rubber reduces fogging Durable Nylon frame Low Volume Sleek and compact 2 Tempered glass lens options: CLEAR - standard AMBER - for increased light, higher contrast and better separation in low visibility All Riffe masks are made of heat treated silicone rubber to reduce fogging. Durable Nylon frame for superior strength. The plastic and silicone mold are of the highest quality and is evident when handling the mask. The Nekton is our Lowest Volume design. It&';s sleek and compact. Created with the freediver in mind. The low volume skirt is comfortable and form fitting, with a tear drop glass lens shape. This offers wider vision span, allowing the diver to see more of their surroundings.