SEAL MASK The Original Swim and Watersports Mask. The patented curved lens provides 180-degree peripheral vision without distortion. The dive-quality silicone skirt provides a comfortable, watertight fit and easy-adjust buckles let you concentrate on your workout - not on your equipment. The Seal was first recognized for its quality by Ironman triathletes but these unparalleled features are equally beneficial to fitness and recreational swimmers alike. Available in a variety of frame colors and four lens types: clear, tinted, mirrored and amber.