I use a Laserlyte rail on my Judge with an Olight PL-Mini 2 light. The Judge has the 3" barrel and fits in a Pro-Tech Holster. I think it's a Size 19, but you might want to check on that. I don't carry the Judge. Instead, I keep it (and the holster) tied around a bedpost with a velcro strap - which gives me easy access at night.