The LG-661 laser sight is an engineering marvel for Smith & Wesson M&P Compact semi-automatics. Interchangeable between calibers, LG-661 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-661 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 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