Mask Plasma C4 Carbon - Black with mirror lenses

Internal volume

The volume of air inside the mask, between the face and the lens, represents the internal volume.

The smaller the volume, the easier it is to balance the mask during your freediving descents

Equalisation

The mask gets pressed against the face when diving down. As you dive, pressure gets applied to the mask's flexible skirt, reducing the internal volume and pressing the mask against the face. This phenomenon, which can cause pain in the eyes, can be avoided by equalising the internal pressure of the mask and the external pressure exerted by the water. Simply breathe out gently through your nose. Air is very valuable in underwater sports, so this equalising effect must be kept to a minimum.

Silicone

Silicone is an extremely flexible material. A silicone skirt conforms gently to the contours of the face, creating a watertight seal.The material is hypoallergenic.