The Holosun HE509T is a fully enclosed pistol red dot sight made by Holosun. This optic is part of Holosun&';s MRS system which means you have 3 reticle options that you can choose from a 2 MOA dot, a 32 MOA circle and a 2 moa dot and 32 moa circle combination.This optic also has 3 modes that you can choose from which include Auto,Manual, and lockout. On the top of the optic si the solar panel which is great for battery retention as well as also having a CR 1632 battery and battery tray located on the right side of the optic. This optic has an amazing 50000 hours of battery life when you are in settings 6.This optic comes with 10 daylight settings and 2 night vision compatible settings when you are in manual mode. Included in the box is user manual, lens cleaning cloth, tools for installation, an adapter plate and screws for the adapter plate. The included 509T RMR adapter plate is not compatible with ZEV or Shadow Systems style RMR interfaces. TECH & FEATURES MRS: Circle Dot; Dot Only; Circle Only Up to 50,000 Hours Battery Life (Setting 6) 12 Brightness Setting: 10 DL & 2 NV Compatible Enclosed Design & Titanium Housing Convenient Tray Battery Compartment Parallax-free & Unlimited Eye Relief In the Box RMR Adapter User Manual Lens Cloth T10 L Key CR1632 Battery