This is the IST Sonic Low Volume Frameless Freediving Mask Features Extreme low volume frameless mask. Made from hypoallergenic liquid silicone. Perfect design for SCUBA and Freediving. Extreme low volume, but with deep nose space for more comfortable fits. Buckle attached on skirt for more flexible without fragile parts. Engrave lines on top for easier clutch. This IST Sonic Freediving Mask features an innovative low volume design. Constructed from hypoallergenic liquid silicone, the mask is ideal for SCUBA and Freediving. With a reduced volume and deep nose space, it provides excellent fit and comfort. The buckle attachment on the skirt eliminates fragile parts while the engrave lines on the top make gripping easier.