These designer prescription glasses are made to accommodate most prescription lenses.Made of Nylon.Liberty Sport Slam Goggle XL frames have a rectangle shape, which helps to balance rounded facial features. Frame shape is the most noticeable feature of a pair of glasses, followed by frame color and frame size. Top brands always have a large collection of rectangle frame shape glasses, as well as oval frame shape glasses.Liberty Sport Slam Goggle XL frames feature a fashionable full frame design, which is the largest component of designer eyeglasses brands collections. A rim all the way around the lenses, provides for maximum stability and durability.The frame has a Unifit.Standard skull temples can be easily adjusted to fit perfectly behind your ears.Material defects or workmanship: 12 month warranty. The warrantee by the manufacturer covers manufacturer's defects for the frame. As an online optical superstore, we can help to process a warrantee for you with the manufacturer, according to their return policy. See all Liberty Sport Liberty Sport Glasses Liberty Sport glasses protective eyewear has been in production by the Liberty Sport company since 1929. Liberty Sport glasses are designed to handle the rigors of sport - unbreakable, tight fitting - and thus perfect for any PPE application. Liberty sport glasses accomodate most kinds of prescription lenses, to be used in hospitals, and sporting activities such as baseball, softball, basketball, squash, and more. All Liberty Sport glasses and Liberty Sport sunglasses can be customized with prescription lenses, just like all of our glasses.