About This ❗❗❗ 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 it’s 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 Overview Brand : BTMETER Material : Plastic Item dimensions L x W x H : 9.88 x 2.83 x 1.18 inches Item Weight : 150 Grams Number of Items : 1