The LG-660 laser sight is an engineering marvel for Smith & Wesson M&P Full-Size pistols. Interchangeable between calibers, the LG-660 Lasergrips directly mimic the look and feel of the original grip, with the tactical impact of laser sighting. Activation is in the rear of the weapon on this model, instinctively springing to life when the pistol is held in a natural firing grip. The LG-660 received the Academy of Excellence Award for "High Tech Product of the Year" in 2008. Product Specifications Product Type: Lasergrips Material: Polymer Attachment: Grip Attachment Activation Location: Rear Activation Sighting: Factory Sighted at 50' Master On/Off Switch: Yes Battery Type: Two #2032 Batteries Laser Battery Life: Over Four Hours Laser Output: 5mW Red Laser Activation Mode: Pressure Activated Laser Visibility: Approx .5 Inch Diameter at 50 Feet Wrench Size: 0.05 User Adjustable: Windage and Elevation Finish: Polymer Grip with Rubber Overmold Activation Pad Installation: User Installed Warranty: Three Year Full Warranty Color: Black Dot Size: Approx. 0.50" at 50'