The Fox goggles feature flat lenses for perfect vision, even at the edges. The gasket is made with hypoallergenic, high-quality TPRto ensure comfort and a perfect seal on most facial profiles. The double-strap is made of silicone to ensure a perfect fit without over-tightening. The Cressi-patented buckle system makes adjusting the strap effortless.Easy replacement of strap and buckle system. The lenses are anti-scratch resistant, 100% UV protection, and anti-fog treated. The Fox are versatile gogglesrecommended for recreational swimming, as well as both indoor and outdoor use.