Redtail Airsoft got a unit of the Theta Optics TO552 holosight and shares the pros and cons of this aiming device. The Theta Optics TO552 Red Dot Sight features an integrated 20mm mount for easy installation on RIS/RAS Picatinny rails. To adjust for windage and elevation, use a flathead screwdriver to turn the appropriate dials and align the target dot with your BB impact. The sight's battery compartment is located at the front, accessible by pulling up the lever and installing batteries.