The usability is there for CQB only and it has to be very dark. The rear lamps are a bit smaller than expected. They went on my PTR91 very easily. I cant see the front sight in the dark unless I use the "1" marker on the drum or the open sight if you will. Don't expect to be blown away by the superior glow like you get on Mepro pistol sights. Nothing special.
Pros: Easy to install.
Cons: Lamps are extremely small and makes them seem dim.
This review was written in the old system and had content requirements that are different than reviews written today.