+1 on the Viridian. I've had one for two years and have never had to readjust it after the initial setup. It's super bright and is shock proof. I've owned two (when I had two SR9's) and both were 100% top notch.I have a Viridian green laser SR model on my Ruger SR40. Really like it but need some funds so I will have to get rid of it. Reallty like it though can see perfectly fine in daylight at range!