Find out the diffrent optics you can mount on your airsoft gun from Theta Optics in this video from Gunfire... "The purpose of Theta Optics™ is not only to provide high quality optical equipment, but also continuously broaden their offer with innovative solutions common to highest quality products. Prior to being introduced to the market, every product undergoes a series of tests. Theta Optics™ is a suggestion for users that seek a high quality product at a reasonable price."