I picked up one of these on a recommendation from a friend for my ccw, ruger lc9. I found one relative cheap online and it arrived pretty quickly. It was easy to install (see link LaserLyte LC9 Laser CK-AMF9 - YouTube) and pretty much good to go out of the packaging. The power button is easy to access. You can switch the laser from constant on to flashing. It also has a 5 minute auto shut off. I haven't taken it to the range just yet but I have noticed a couple differences that I'm not too sure I like. This laser mounts to the side, above the trigger. I was taught to rest my index finger above the trigger and only on the trigger when firing. With the side mounted laser, my natural resting position blocks the laser and i have to slide my index lower in order to unblock the laser. Also, with the side mount, it does increase the width (girth?) of the weapon. One of the reasons I like the lc9 is that it is relatively thin and relatively easy to conceal. I had considered getting the lasermax centerfire but didn't like the idea of having to get a new holster. However, I'm reconsidering as I'm not too sure I like the added width of the side mounted laser. So, I wondering if anyone else has installed the side mounted laser and what their thoughts are.