Replacement Wind Sensor Wand for BTMETER BT-856A BT-846A Pro HVAC Anemometer - (Sensor Vane ONLY, Anemometer NOT Included) Product Description IMPORTANT NOTE This separated wind sensor fan does NOT include the anemometer,it must to work with BT-856A/ BT-846A anemometer for measurement Original Air Flow Sensor: Replacement USB wind sensor for your BTMETER BT-846A BT-856A Pro HVAC CFM meter, just plug the sensor into the main body, then its ready to use Low Friction Impeller: A low friction impeller can help you pick up the low winds down to 0.001 and give you an accurate reading. Wide Measurement Range: Higher Wind Speed Range: 0.001~100 mph (Accuracy: +/- 3% +/- 0.2 reading), Resolution: 0.001. Air temperature range 32.0-113.0 (0~45), Resolution 0.1 Replaceable Wind Pickup Sensor: Extendable separated wind sensor, Allowing to measure wind speed, air flow from higher and further areas that may not be accessible if you use a integrated anemometer Product Specification: Wind Velocity Range: 0.001~100 mph Speed units: m/s, km/h, ft/min, knots, mph Resolution: 0.001 Wind Temp Range: 32.0 - 113.0 Compatible with HVAC anemometers: BT-856A/ BT-846A