National Geographic Snorkeler Tunny 6S Jr. Experience Mask National Geographic Snorkler "Experience Series" Masks The best choice for people who want to simply experience snorkeling - Pearl Black Low Profile Double pane CE Tempered lenses. Frame-Lightweight Delrin and plastic. Mask Strap-flexible and replaceable with - 3 point hold. Ratchet Quick lock (RQL)- mask strap adjustment Mask Skirt-feathered edge seal Nosepiece-pliable and non-feathered for ease of draining