Aqua Sphere Defy Ultra Swim MaskExperience infinite vision and conquer open waters with the Defy. Ultra. Our new swim mask features an all new DuoCurve lens, offering panoramic vision both laterally and vertically, ultra thin silicone Precision Fit technology skirt for a comfortable, leak free seal and a groundbreaking ultra light frameless design thanks to our Cool Inject Technology for reduced drag in the water. Prepare to lock in your new personal best time with a low profile