Right. It's the Safariland RLS (Rapid Light System). You can get just the mount and it's about $30. It will fit any 1" light. You can find the mount plus light online for around $85. I really like the light because it has a 65 Lumen LED that uses 3 AAA batteries (in a cool little holder). The run time is 50 hours instead of the normal 10 or 12 with a 123 battery LED.
My carry holster doesn't accommodate a mounted light. I can carry this one on my belt, and because it's a regular 1" light, I can use it for regular flashlight needs. I don't have to carry a flashlight and a weapons-mounted light. Then, when you need it, it's on your rail in less than a second. It's so easy, you wonder why it took people this long to figure it out.
Anyway, I didn't remember seeing it in any discussion on this forum before. I just wanted to bring it to everyone's attention.
I don't think it will work with that light. I checked the diameter for the Felix, and it's 2.1cm or about .83". That means that it would be too small to fit in the mount. The mount is made for a 1" light (.970" to 1.060").
You might be able to rig something up, but I'm not sure.