It works, but there are problems - Laser Genetics ND-3AR All Weather Subzero Green Laser Designator

Pros
Seems to work as other reviewers say: At night will illuminate a target out to maybe 200yds. Max beam tightness is about 2", and maintains this pretty well at range; beam dot is visible out to at least 1/3 mile. (Of course, such a tight beam can be used as a laser sight, but it will not illuminate/identify the target, so you need some other way to do that; got to see what you're aiming at!).
When the beam is aligned so its center is aligned with your sights, should work well as a combo flashlight and laser sight for nighttime home defense. At close ranges indoors, even a rather tight beam setting gives off enough peripheral light to see what you're doing, so you can use the one device to both identify and aim at a target.
Seems generally built fairly tough.
Cons
But...the screw/pin that clamps the unit to your rail is thin and flat at the end where it attaches to the QD lever, and there's a hole drilled into the flat end so the lever can be attached to it. There's so little metal there that the flat end of the clamping pin just snapped right at that hole the first time I tried to attach it to the rail. Yes, I could have been more careful, but I see no way it would have held up over time. Rather than return the unit I just installed an 8-32 bolt and a finger knob. It'll hold really well now, though I've lost the QD capability.
To test the low temp operability, I put it in the freezer @ 10F for an hour, then took it out to try it. It did light up, but it was so weak it could not have been used. After warming up a bit to maybe 30F it perked up to a usable level. I'd guess if using outdoors in freezing weather, a handwarmer would keep her operational, so I don't consider that a problem, but the stated specs are too optimistic.
The advertising is a bit deceptive in another respect: The stated power is 15mw, but when you get the manual you find that the laser itself is 5mw, and the output is 15mw. In contrast, the Ade Advanced Optics Laser Designator advertises the same laser power, but an output of 40mw. IF both companies figures are accurate, the Ade device should put out a lot more light. (On the other hand, I hear the Ade is no good at temps below 40F.)
Overall, the ND3 works for me. Be ready to do a little gunsmithing on the QD though.