The CRESSI Sirena Mask has a Single Lens, and is designed for Snorkeling, Swimming and Scuba Diving. The Masks Skirt is made from Soft Hypoallergenic Black Silicone with a Double Feathered Edge for an Excellent Seal on Most-Face Types. The Wide Split Strap further Enhances to Masks Sealing ability. The Visibility provided by the Single Tempered Glass Lens and the Unusual-Shape of the Frame Extends-in-All-Directions. This Medium Volume Mask has Quick-Release Strap Buckles for Easy-Adjustments. Mask is equipped with an Easy-to-Reach One-Hand Nose Pocket for Ear Equalization which can be utilized even when wearing thick gloves. Mask is covered by a 12 month limited warranty.