The HS515GM is an ultra durable 20mm micro sight designed for hard-use rifle and carbine applications. The HS515GM is made from 7075 aluminum and includes clear, removable/rotating lens caps, a QD lower 1/3 co-witness (1.63”) mount, and is IP68 certified waterproof and dustproof rating. The HS515GM is one of our favourite "T1/T2" style red dots due to its optical quality, selectable reticles, protected turrets, night vision-compatible brightness settings, daylight-bright reticle, and subdued markings. Additional features include our MRS (Multi-Reticle System) with Red Super LED, 10 daylight and 2 night vision compatible reticle intensity settings, Shake Awake technology, and up to 50k hour battery life. The battery is housed beneath a side mounted cap for a tool-less replacement. The HS515GM is designed for sporting and professional users. Specifications: Reticle 2 MOA Dot & 65 MOA Circle Light Wavelength 650nm Reticle Colour Red Parallax Free Yes Magnification 1x Power Source Battery Battery Type CR2032 Battery Life 50000 hours Brightness Settings 8 Daylight; 4 NV Window Size 20mm diameter Dimensions 2.73 x 1.53 x 1.61 inches Weight 3.74 oz Material 7075 T6 Aluminum Adjustments per click 0.5 MOA Windage & Elevation Travel +/- 50 MOA Operating Temperature -30C to 60C Waterproof IPX8 Vibration 1000G