The AimpointA(R) CompM4 sight belongs to the CompM4 series which has made vast improvements to its energy efficiency by providing 8 years of continuous use from one single AA battery. The CompM4 is the toughest, tried and true sight Aimpoint has ever produced and is the standard for military combat. Product Specs: Optical Magnification: 1xAiming Dot Size: 2 MOABattery Type: AABattery Life: 80,000 hours Length (sight only): 4 A 3/4"Length Configured: 5 5/16"Width: 2 13/16"Height (sight only): 2 3/8"Height Configured: 2 3/16"Weight (including battery): 9.4 oz.