TUSAs first frameless scuba diving mask, complete with our innovative technology, panoramic view, and lightweight design. The Fabric Mask Strap adds a new level of comfort to the dive experience. Anti-slip grip and easy adjustment ensures a snug fit to the back of the head. The snorkel keeper ensures secure placement. Fabric Strap Features: Easy size adjustment. Anti-slip on the back of the head. With snorkel holder. Head Circumference Size: 500-650mm. Material: Polyester and Nylon. Mask Features: 3D SYNQ - A unique Fitting Ring built into the Mask Skirt providing an ideal fit for all face shapes. Swift Buckle 3D - A new low-profile buckle and mask strap for smooth effortless adjustments. Freedom Technology/Freedom Dry - Enhances comfort and fit by utilizing a revolutionary low friction skirt surface. Round Edge Skirt - Round edge skirt improves both seal and comfort of the mask. Panoramic View - Mask providing an extra wide field of view.