Works as advertised, well made, but in the end not for me - Viridian Reactor 5 Green Laser Sight for Smith & Wesson M&P Shield with ECR Hybrid Belt Holster

It seems to be of good quality, well packed, and installed easily on my Performance Center Shield 9 MM. It came with batteries and the allen key needed to adjust windage and elevation on the laser. I shot a few hundred rounds and the setting held. The green laser shows at 75' on a cloudless day. It may go further, 75' was the depth of the range I was at.

The SKU I picked came with a Kydex holster. There is a small magnet in the holster. When the gun is next to the magnet (holstered), the laser turns off. when you draw it out (away from the magnet), the laser activates. You may be able to retrofit a holster if you can affix a magnet where the laser rests.

This was my first laser and I found some negatives after using it.
The button on the side to change modes is hard to use. You cannot change modes while holding the gun. However you have it setup is how it will run when you need to grab it and be ready for action.

With the laster being on all the time, you telegraph your movement. If your searching your house in the dark, intruders will have advance notice of your approach down a hall or from another room.

For use at night, you really need a light to identify your target and ensure its not a family member up and about.

If the price works for you and these negatives are not a concern, then it's a good choice.

I bought a Shield 45 with a Crimson Trace Light/green laser combo that extends a button to the grip. Hold the grip tight and light/laser comes on. Loosen your grip and it goes off. I think this is a better solution. If purchased on the gun from S&W, the price is very reasonable. It costs much more to add the laser separately after the purchase.

Why change to the 45? The ported barrel on the Performance Center Shield blows up and gets grit in your face/eyes. Without glasses, you can be left blinded after the first shot. You can hold it sideways or at an angle to compensate, but that may not hold up in a high stress situation. Being called upon to draw your gun is high stress. Rather than get another 9, I went to the just out 45. I like the 9 MM and use it at the range.