Hello, I am Adco SOLO Multi-reticle Red Dot Sight, your official and early red dot sight model first appeared in January 2011. There are a lot of red dot sights like Bushnell, JH-406, Sightmark Sure Shot, Walther MRS, GVT Tactical Sight, Feyachi RS-28,... share the same design like me. But I am the official one.