I use this on my Prime C2 Pro. The rubber surround of the lens grips onto the body of the light well and will not come off even when I"m trail running. I like that the lens is recessed into the rubber frame so that it doesn't get scratched or come into contact with things easily. It diffuses the light such that the angle is somewhere between the Wizard and the Prime without the diffuser. It makes the light more versatile and is highly recommended.