I've got the old 250yd model. It works fine and mounts on an inverted Weaver-style scope ring. I think they have changed the mount system to require an optional adapter if a 30mm scope tube is used. (I call it engineered revenue)

Be advised the red lens IME will cut advertised effective range essentially in half. Mine is useable out to about 120yds.

Here is another opition if you want to "kick it up a notch": Link to Lightforce Lights Dealer

Good Hunting,

Bob