From what I've found online, the regular (older) Radar Path lenses are not compatible/interchangeable with the new Radar Lock Path frames. I talked to Oakley's customer service this morning and was told that the regular Path lenses can actually be used in the Radar Lock Path frames. It's not "official", but the customer rep said he actually did it himself with his own Radar Locks. I then went to my local O Store, where I was told the same, and the sales associate even showed it to me by inserting a regular Radar Path lens into the Radar Lock Path frame. It doesn't work with the Radar Edge lens, but I don't really care, since the Path shape is my favorite. Now my problem is that I put the regular Radar Path and the Radar Lock Path lenses side by side, and there are small differences in the width and shape of the nose area, as well as the small "hooking" parts at the two extremes of the lens (which attach into the frame). I wonder if it's safe to use the regular Radar Path lenses with a frame they were not designed for. Could it result in long-term damage to the switch-lock mechanism of the Radar Lock frames? I've also noticed the Radar Lock's nosepiece (which is very slightly thinner than the regular Radar Lock's) does not fit 100% the regular Radar lens (there is a very tiny little gap), though they seemed attached pretty sturdily when the guy did the demo for me. The problem is that Radar Lock replacement lenses will not be available for a while and I'd like to buy a VR28 or G30 lens for my Radar Locks, but I'm not sure it's entirely safe to do so with the regular Radar lens.