The FINA Approved Mad Wave Racer goggles are designed for competition and performance. The low profile racing goggles in the Swedish style, have been developed to produce minimal drag. The reduction in drag is achieved with streamlined low profile lenses, the absence of a hard frame and no eye gaskets. The polycarbonate lenses fit directly into the eye socket, unlike regular goggles which have silicone/TPR gaskets. The lenses provide UV protection and have an anti-fog coating to ensure great all-around vision. As with most Swedish style goggles self assembly is required.Assembly Instructions:1. Thread the fixing thread through the first lens using the small hole located at the side of the lens.2. Slide the blue nose bridge cover over the other end of the fixing thread.3. Thread the loose end of the fixing thread through the remaining lens and tie with a knot.4. By sliding the string, you should be able to hide the knot inside the blue nose bridge cover.5. To attach the rubber strap, push each end of the rubber strap through the opening on the edge of the lens.6. Pull equal lengths through the lens holes, then use the plastic retainer strap adjuster to adjust the strap to the correct length.