Crimson Trace lasers can not be used on different weapons. I want ONE laser/light combo that will work on my Rem. 870 shotgun, my HK91 and my Glock. I found that the Streamlight TLR-2 with optional shotgun mount ($15) will work on all 3 weapons. I choose this one because;
1. It has a lifetime warranty
2.Has all aluminum construction instead of plastic
3. Uses LED which never burns out and is super reliable.
4.You can use light, laser, light and/or laser at same time with light.
5. Very long run time.
6. I really liked Streanlight's customer service. I had a old well used Streamlight XL 20 and when it did not work they replaced it for free years later.
7. Found a very good price of $199 at Biotach which is $50 less than any other place.
I believe this is the right choice for me.