The Holosun Elite Green Dot HS403B-GR is a rifle collimator sight with a closed design, featuring an aluminum housing, Shake Awake battery saving system and two mounting bases. The Holosun Red Dot HS403B-GR is designed for the use of long guns including AR15 carbines, semi-automatic rifles. Lightweight construction The body of the sight is made of 6061-T6 aluminum by precision milling. The device has a lightweight and durable design weighing with a high mount only 124 g. The Holosun Elite Green Dot HS403B-GR features "stable zero holding", has no parallax error, and its optics provide unlimited eye relief, making it suitable for use on sporting rifles, AR carbines and hunting weapons. Optics The Holosun Holosun Elite Green Dot HS403B-GR uses lenses coated with multi-layer anti-reflective coatings, which provide high light transmission and a clear and sharp image free of parallax error. Electronic system Thecontrol system and diode are resistant to shock (1000 G), weapon recoil and weather conditions, making the device work efficiently and stably on hunting and sporting weapons. Universal aiming point The sight uses a 2 MOA green dot aim ing point. The green LED provides a higher contrast of the aiming point against the background of the environment, this color is better perceived by humans and at the same time the least tiring to the eyes. Battery saving system The device'simpressive runtime of up to 50,000 hours is due to the Shake Awake system , which automatically turns off the LED when there is no activity and the device goes into sleep mode. Re-activating the aiming mark requires only moving the weapon. The user can independently define the time after which the sleep mode is activated. Convenient battery installation An element that many shooters pay a lot of attention to is the way the battery is mounted. In the Holosun Elite Green Dot HS403B-GR, the battery is mounted on a sliding tray, secured by two Torx screws. Such functionality allows changing the battery without removing the collimator from the weapon, as is the case with models with the battery located on the underside. Two mounts The set includes two Picatinny/Weaver rail mount s : a high one (1/3 co-witness) intended mainly for carbines and a low one recommended for shotguns.