These new polycarbonate clip-ons in cobalt blue shades, fit on your existing safety glasses. They have an integral spring clip that attaches to the bridge of your glasses. They can be flipped down when protection is needed for molten metal observation, torching or brazing. And can be flipped back up when not needed. They are super light and very durable. They offer excellent UV protection as well. Available in Shades 4, 6 and 8.