An important structural feature of this mask is that it lacks a rigid frame. This allows the mask to be folded in half, bending around the nose area. We recommend using this model as a spare mask for technical divers (as it easily fits into any pocket). This diving mask has a medium-sized mask volume. It has a comfortable shape suitable for most face types. The mask seal is made of soft hypoallergenic silicone, and the lenses are made of tempered glass. The lenses are directly installed into the silicone seal, reducing the mask's volume and expanding the field of view.