The JDC Xplorer 4 Anemometer, Thermometer, Digital Compass, Altimeter, Barometer is simple to use. Press one button, and instant readings are at your fingertips. Designed for the consumer and professional in Switzerland, the Xplorer 1 is built to demanding specifations and engineered to provide a lifetime of accurate and dependable use. XPLORER FEATURES: Dimension: 3.5 x 1.5 x 0.75 in, 2 oz. (41 x 93 x 17 mm, 50 g) - One button operation - EL Backlight - Completely sealed; internal sensors - Weatherproof (can be submerged 6 feet) - Replaceable Lithium battery (included and installed) - Stainless steel back - Auto-off after one minute (can be disabled to remain on) - Included lanyard - One year warranty - Designed in Switzerland - WIND SPEED SPECIFICATIONS: - Balanced impeller is integrated into wind meter - The impeller is magnatized, producing a magnetic field when rotating which is measured internally - Damage to the impeller is unlikely due to the small opening, but repair can be performed - Units: km/h, mph, m/s, fps, knots - Range: Max 94 mph (150 km/h) - Resolution: 0.1 unit - Precision: +/- 3% - Measuring cycle: Twice per second. TEMPERATURE FEATURES AND SPECIFICATIONS: Internal thermometer is attached to the stainless steel back - Temperature adjusts quickly, although drastic temperature changes may require several minutes for accuracy - Temperature is read quickly by touching the back to an object of the same temperature - Water temperature is read quickly by submerging the unit briefly - Units: °F, °C - Range: -58°F to 212°F (-50°C to 100°C) - Resolution: 0.1 unit - Precision: +/- 0.5°F (0.3°C) - Measuring cycle: Twice per second. DIGITAL COMPASS FEATURES AND SPECIFICATIONS: Designed to be used in verticle position - Will display windspeed and compass simultaneously - Electronic calibration before use ensures absolute precision (easy process) - Units: Degrees off North - Range: 0 - 359° - Resolution: 1 degree - Precision: +/- 4 degrees - Measuring cycle: Twice per second - ALTITUDE: Altitude is based on an initial set altitude and a change in air pressure (this is true of ALL altimeters). Drastic air pressure variance (weather front) will impact altitude readings (usually occurs over 12+ hours). Several seconds is needed to adjust to new altitude. The highest accuracy is acheived when the altitude is properly set, a change in altitude is more than 10 feet, and several seconds are allowed for adjustment. For example, the Xplorer 4 may be moved from one level of a house to another, and a change of 10 feet will be recorded (standard ceiling height). Altitude and air pressure are measured on the same sensor, and adjusting one will adjust the other. Altitude history is recorded every hour for the past 48 hours. See instruction manual for more details: Units: feet, meters - Range: -2,300 to 29,500 ft (-700 to 9,000 m) - Resolution: 3 feet (1 meter) - Precision: +/- 33 ft (10 m) - Measuring cycle: One second - AIR PRESSURE: Air pressure is read in either "relative" or "absolute" air pressure - Absolute air pressure is a precisely defined measurement, just like temperature - Absolute air pressure is measured within .10 inHg, and cannot be adjusted - Relative air pressure is the most common unit used in the US - Relative air pressure factors out the change in elevation, essentailly calculating the air pressure at sea level - Relative air pressure is adjusted to reflect current altitude - Once the relative air pressure is set, if no changes to altitude occur the accuracy is within 0.01 inHg - The most important factor in changing weather is the change in air pressure - Rising air pressure indicates better weather, falling air pressure indicates worsenign weather - With the air pressure history, one can accurately predict future weather - Air pressure history is recorded every hour for the past 48 hours, although the past 6-12 hours is most important - See instruction manual for more detail. Units: inHg, hPa - Range: 8.86 to 32.50 inHg (300 to 1100 hPa) - Resolution: .01 inHg (1 hPa) - Precision: +/- 0.10 inHg (3 hPa) - Measuring cycle: One second. MSRP: $170.00. Normally ships in 1-2 business days.