Viridian green laser reactor 5 - Viridian Reactor 5 Green Laser Sight for Smith & Wesson M&P Shield with ECR Hybrid Belt Holster

This is a very good product, and compared to the competition, an excellent value. I like green lasers because they are not only easier to see in daylight, but in the dark, they also light up the environment enough that I personally don't think a tactical light is necessary. There is enough light scattered to tell exactly what is in the room with you. This unit fits my S&W Shield perfectly, and was easy to install. Sighting in was the same experience I have had previously with a Crimson Trace Laserguard on another of my guns in that it was necessary to readjust after shooting several rounds to allow the adjustments to seat in.
Two things are of concern.
1. It is not easy to turn the laser on and off with the button. This could definitely be a tactical concern. The light does turn on and off easily when removed from and returned to the supplied holster, however, depending on the situation, this may not be an option.
2. There is no battery door per se. It is necessary to split the halves to access the batteries. My experience with green lasers is that battery life is significantly less than red ones, so battery access may be an issue in the future.
Other than that, I'm pleased with both the unit, and the supplied holster. It is an IWB model that actually fits me and is comfortable to wear, which had previously been a challenge of its own.