Round square shape with polarized lenses. Polarized lenses are lighter weight on your glass frame and the polarized lenses reduce the most glare. For the round square shape to fit your glasses, your glasses need to be round square in shape with your frame rim measuring less than 3mm's thick. Measure one lens of your glasses carefully to the outside rim of your glasses width x height. We have many different sizes available and only one will fit your glasses, so it is very important to measure your glasses correctly. The round square shape needs to be nearly the same shape as your glasses and the size clip-on sunglass needs to be the same as the measurement of your glasses or the next size bigger. To help with sizing, we have printable templates for the round square shape at Sunglass Rage but there isn't a way to upload the templates here so measuring your glasses carefully is very important. All of our sunglasses and clip-on's are rated UV400 protection which is up to 100% protection. We include a microfiber pouch to store and clean your lenses.