The Blue Tees Golf Series S4 Ultra Laser Rangefinder with Slope is a high-powered device with a magnetic strip, powered by batteries. It has a range of 1200 yards and features waterproof construction, Fast Focus System, Slope Switch Technology, and Dual Display Technology. The Series 4 Ultra is our new high end, premium laser rangefinder. OLED Display – Ultra Mag Strip – Slope Switch – Auto Depth Filter – Active Track – Brightness Control. Advanced Flag Lock – Pulse Vibration – 1200 Range – IP54 Weather Resistant.