I realy like this. - Crimson Trace Laserguard Green Laser Sight for Springfield Full Size XD / XDM

I installed this laser on my bi-tone XDM .45 and I have been very happy with it. I have taken it to the range twice now and it is holding zero very well. The activation button is located under your ring finger for intuitive activation but little risk of unintentional activation the way the style that wraps around the back can have.
There is an on/off switch on the front of the housing to disable the activation button so the laser will not activate. I find this a great feature for zeroing and practicing with the iron sights.
The green laser is very bright and while it is no substitute for a proper weapons light, if I shine it on a light colored surface (such as a wall)it will light up the area of a child's dark bedroom enough to see who is in it.
The unit installs easily and the whole thing integrates seamlessly into the frame. Plus it just looks cool.
It uses the exact same housing as the LG-453 Lightguard so the same holster can be used for both, but that brings me to it's one great drawback. There is limited holster availability. A couple of companies like CrossBreed make very nice belt slide style holsters to fit this set up, but I have found no paddle shoulders, tactical holsters, or shoulder holsters designed specifically for this combination. I do not care much for general fit style holsters.
In all I like this laser. It installs easily, works well, is not bulky, and looks cool. Admit it, you like it when things do not just work well but also make your gun look cooler.