Ambient Weather WM-4 Handheld Weather Station w/Windspeed, Direction, Temperature, Humidity, Compass, Dew Point, Comfort Index, Psychrometer

Features:
Current wind speed, Maximum wind speed, Average wind speed
Wind measurement units: knots, mph, kph, feet/minute, meters/second, Beaufort
Wind direction in degrees and compass points
Calculates cross wind, head/tail wind
Current temperature (°F or °C)
Current dew point (°F or °C)
Current wet bulb (°F or °C)
Current wind chill (°F or °C)
Current relative humidity (%RH)
Current Delta T
AccuWeather.com patented Comfort Index
USA fluxgate compass
Swiss-made impeller
Lifetime calibrated Swiss-made humidity sensor
Backlit LCD display
Auto shutoff after 5-min
Threaded for tripod mounting
Pocket-knife design to protect unit when not in use
Adjustable lanyard
Water resistant and floats
Specifications:
Wind speed range: .8-89 mph
Wind speed accuracy: ±3% when aligned with winds axis
Current wind response time: 1-sec
Avg wind response time: over 10 sec
Max wind response time: 1-sec
Cross wind head/tail wind response time: 5 sec
Wind direction response time: 1 sec
Temperature range: -20° to +158°F
Temperature accuracy: ±1.8°F
Temperature response time: 1 min
Dew point range: -20° to +158°F
Dew point accuracy: ±3.6°F
Dew point response time: 1 min
Wet bulb accuracy: ±3.6°F
Wet bulb range: 32° to 100°F
Wet bulb response time: 1-min
Wind chill range: -50° to +50°F
Wind chill accuracy: ±1.8°F
Wind chill response time: 1 sec
Rel. humidity range: 5-95%
Rel. humidity accuracy: ±3%
Rel. humidity response time: 1 min
Delta T response time: 1-min
Compass accuracy: ±2°
Compass range: 0 to 360
Compass response time: 1 sec
Other Specifications:
Power: CR2032 Lithium battery (included and replaceable)
Dimensions: 5.5" x 1.75" x .75"