Specification: Item Type: Tower crane anemometer Material: Aluminium alloy, ABS Weight: Approx. 990g / 34.9oz Power Supply: USB 5V Input Voltage(Actual Withstand Voltage): 220V Product Size(host): 18.3x10.5x5.1cm / 7.2x4.1x2in Host Installation Diameter: 17cm / 6.7in Fan Blade Installation Diameter: 4cm / 1.6in Fan Blade Cable: 8m / 26.2ft Application: Weather station, wind speed measurement Wind Level Accuracy: 0.3 level Setting Wind Level: 2 to 12 levels (can be set sequentially at 0.5 levels each time) Accuracy: ±5% Starting Wind Speed: 0.7m/s Working Temperature: -30-65°C Package List: 1 x Host 1 x Connection Cable 1 x Fixing Bracket 1 x Bracket Accessory 5 x Screw 5 x Nut 1 x Fan Blade with Cable Features POWER CONTROL FUNCTION: This wind speed alarm can control the equipment that you want to control in case of an emergency, and automatically cut off power when the wind speed reaches the set level. 3 FAN BLADES DESIGN: This wind speed meter uses a 3 fan blades for accurate 360 degrees wind speed measurement, ensuring high accuracy. WIDE MEASUREMENT RANGE: The wind speed alarm meter has a wide measurement range and strong anti interference ability, with built in electromagnetic interference resistance. POWER FAILURE MEMORY FUNCTION: This wind speed meter uses a CMOS chip with power failure memory function, saving time and energy. WIND SPEED DISPLAY: The display of this wind speed alarm shows various wind values including current actual wind speed, wind speed level and maximum wind speed level, providing you with pleasant experience.