What type of handgun do you have?
Do you want a below the barrel sight? Or have you looked into Crimson Trace grip replacements that do the same job?
Have you seen the guide rod replacement pieces that also double as a laser?
Now, the important question: Do you realize that lasers point two ways and by "lighting someone up" you are also telling them RIGHT where you are?
Not judging, I put a laser on two pistols I have had in the past and there was no talking me out of it. Just trying to impart a little been there wisdom.