Hollis M-4 Frameless Mask NAVCON enriched air – the M1

enriched air – the M1 is perfect for recreational divers ready to extend their capabilities or accomplished technical and specialty divers

The unit turns off automatically when the headphone/microphone is removed

Depth Compensating

Large Easy to Reach One-Handed Nose Pocket for Ear Equalization

Hollis M-4 Frameless Mask NAVCON enriched air – the M1This products Overview When choosing a mask, fit and field of vision come first. The M 4 gives you the best of both worlds, fitting a wide variety of faces and offering superior peripheral and vertical vision. It is low profile, stows easy and carries an excellent value. Mask has a single lens made from tempered glass for excellent optical characteristics and safety. The frameless black silicone skirt has a double feathered edge for a perfect seal,