The Frameless mask is the latest in mask technology. Tri-view S-M fits narrow and avarage faces. The silicone skirt is made of liquid silicone and fastened directly to the glass instead of the usual plastic frame. This gives an exceptionally good field of vision as well as an extremely low volume. Furthermore this model is equipped with side windows that improve the line of sight on both sides. Tempered glass for optimum strength. Swivel buckles on the strap. Comes packed in a storage box which provides protection.