ATN 6015-4 Gen 4 Night Vision Multi Purpose Monocular is rugged, lightweight and versatile designed for the most demanding of night applications. Unit can be hand held, head/helmet mounted for hands free usage with the included US Mil spec headgear, or adapted to cameras/ camcorders for night-time photography (optional adapter). Originally designed for the US Military, these units are of the highest quality in optics, design and functionality. An outstanding choice for professional night vision applications. Requires one 1.5V AA size battery, included. ATN Corp manufactures and distributes the widest array of Night Vision and high quality optics in the world. We are a sales and market leader in the US. Unsurpassed customer service on both our website and 800#, our technicians are the most knowledgeable in the world. We manufacture for the US Military, law enforcement, the FBI and the US Department of Homeland Security.