Series 2 Pro Slope Pro level technology adjusts distance based on the incline/decline for "True Distance" Flag Lock with Pulse Vibration emits short vibrating pulses to confirm lock onto target, not what's behind it Measure targets up to 800 yards away with an accuracy of +/- 1 yard. Adjustable EZ Optic Focus for high definition viewing Water resistant construction In the Box Series 2 Pro USC Rangefinder Hard shell carrying case Microfiber cleaning cloth CR2-3V battery