The MK-III sensor assembly has been designed to offer improved durability and serviceability. This sleek new design is 33 inches high and weighs just over 7 pounds. It is the most accurate, durable and easiest to install weather station available. The long range MK-III-LR features a powerful new 2.4 GHz spread spectrum radio that increases range to 1 mile line of sight. It also features an industry best , real time 2 second wind speed and direction update interval. Features: The solar charged battery supply is guaranteed to provide continues operation below 60 degrees latitude. The MK III will operate for at least 60 days without sun. Since there is no connection between the sensors and the power line, damage from thunderstorms is virtually eliminated and the sensors are immune to power line voltage surges. The initial sensor calibrations for wind, temperature, relative humidity and barometric pressure are traceable to the National Institute of Standards and Technology. The passive solar shield for the temperature and humidity sensors are modeled after the ones designed by the National Weather Service.All materials used in the sensor assembly and weather instruments have been chosen for their durability and resistance to weathering and corrosion. All of our weather station hardware is stainless steel. The station is fabricated from fiberglass and structural PVC and is ultra-violet inhibited. The optional Mono Mount is made from powder coated steel and is supplied with bolts for mounting. Specifications: Wind Speed ( Anemometer) : Range: 0 - 150 mph.; 0 - 67 meters per second; 0 - 240 Kilometers per hour; 0 - 130 Knots. Resolution: 1.0 unit. Accuracy: ± 2% of full scale. Wind Direction: Range: Oracle Display has 16-point wind rose, current direction by bright LED, and direction variation by dimmer LED' s. Computer interface gives reading in degrees, 360° = North, 090° = East. Temperature-Outside: Range: -66° to + 166° F; -54° to + 74° C. Accuracy: ± 1° F; ± 0.5° C. Temperature- Inside: Range: 32° to + 122° F; 0° to + 50° C. Accuracy: ± 1.0° F; ± 0.5° C. Relative Humidity: Range: 0 to 100 % R.H. Accuracy: ± 2 % at 25° C. Temperature compensated from -40° to 85° C. Dew Point: Range: -40° to + 140° F. Accuracy: ± 2° F, ± 1.0° C. Temperature/ Head Index: Range: To 160° F, 71° C. Accuracy: ± 2.0° , ± 1.0° C.. Wind Chill: Range: to -127° F; to -88° C. Accuracy: ± 2° F, ± 1.0° C. Barometer: Range: 16.3 inches Hg. to 32 inches Hg; 551 to 1084 millibars ( hPa) , absolute reading. Digital offset for site altitude. Accuracy: ± 0.05 inches Hg; ± 1.69 millibars ( hPa) at 25° C. Temperature compensated from -40° to 85° C. Rainfall: Range: Unlimited Tipping bucket with 8-inch diameter collector. Resolution: 0.01 " ; 0.25 mm. Accuracy: ± 2% at 1 inch per hour. Transceivers: Range: Up to one-mile line of sight. Walls or other RF absorbing structures may reduce range. Frequency: 2.4 GHz spread spectrum 802.15.4. F.C.C. approved.