The Original Panoramic uses technology that allows the glass joint to virtually disappear, creating less distortion compared to other 3 window masks. Available in Single or Double lens and Purge or Non-purge. The Double lens also comes in a Junior/Narrow size. The Sleek Dry Snorkel has a drop away mouthpiece which keep the snorkel out of the way when you switch to your regulator. Snorkel feature a dry top which keeps water out when the snorkel is submerged. The bottom purge makes it very easy to clear the snorkel of any water that may find it's way in.