Holosuns newest SCS (Solar Charging Sight), the SCS-MP2-GR was designed to fit the Smith & Wesson M&P-M2.0 full size, 9mm & 40 S&W handguns (will not fit 1.0 or Shield models). It is designed to attach directly to the slide without an adapter plate and uses our innovative solar charging system with multi-directional light sensors to automatically adjust brightness in dynamic situations. The SCS can potentially operate indefinitely using an internal, rechargeable 20,000-hour power reserve meaning under even moderate exposure to bright light, you will never need to change batteries again. The SCS also includes an intensity override function which locks the optic into a high brightness mode for 30 minutes and a low power indicator, which will signal if charging is needed upon system start up. Specifications for Holosun SCS MP2 1x9 mm 2 MOA Red Dot Sight for Smith & Wesson: Manufacturer: Holosun Color: Black Fabric/Material: 7075 T6 Aluminum Magnification: 1 x Objective Lens Diameter: 9 mm Reticle: 2 MOA Dot & 32 MOA Circle Illumination Type: LED Brightness Settings: 0 Emitter Type: Open Water Resistance Level: IP67 Gun Make: Smith & Wesson Gun Model: Smith & Wesson M&P 40, Smith & Wesson M&P M2.0 Height: 1.93 in Weight: 1.3 oz Condition: New Gun Type: Pistol Rear Sight Color: Green Front Material: Aluminum Package Contents: Holosun SCS MP2 Red Dot Sight For Smith & Wesson Multi Tool Lens Cloth User Manual