UV400 non polarized yellow lens rectangular shape flip-up that clips onto rectangle shape prescription glasses. Measure your glasses width x height. It is best to add about 2mm's to the height of the flip up height to accommodate for how the flip up clamps onto your glasses. It is usually okay for the flip up lens to be a little wider or higher than your glasses, it will just overlap a little.
One Lens 56mm Width x 40mm Height
Total Width 128mm x 40mm Height
One Lens 58mm Width x 42mm Height Total Width 130mm x 42mm Height