Your looking for the ess u-rx insert, works very well for me at leastI love those OverTheTop frames, really takes me back! I am currently down to my old pair of Acid green Frogskins. I had some favorite Anti-Freeze Radars in the past when working at bicycle shop but lost them to gnarly crashes unfortunately. Definitely looking into that Rx insert for a next pair of Oakleys, I love that updated m-frame look of the Radars. I had the EyeJackets for years and a few pairs of Zeros I wish they would bring back of course. Nothing beats a nice weird pair of Oakleys on the bike ride!