Mares X-Vu mask X-VU Stylish and comfortable Tri-comfort Skirt 2-button buckles on the skirt X-shaped strap The front portion of the X-vu scuba mask skirt has a series of horizontal bumpers made to absorb any relative movement between the mask and the face. This diminishes the sensation of squeezing on the face and the forehead, which can be especially appreciated during long dives. The X-shaped strap improves the overall fit of the scuba mask. The two-button buckles allow for a quick and effortless strap adjustment.