The Multi Rectile Open Reflex Sight features a W33 x H22 mm lens for fast targeting. Due to the wide field of view, you are more aware of your surroundings and you experience little visual obstruction. The Tactical Open Reflex Sight can be mounted on any 20 - 22 mm RIS and runs on one CR2032 battery (not included). The unique thing about the sight is that you can choose from different types of reticles. The sight can be calibrated both horizontally and vertically. A protective cover is included to protect your sight during transport.