Even without taking into account the unique, astonishing way it wirelessly connects with a smartphone, the Vaavud wind meter is pretty neat little gadget.

It will measure wind speeds up to 25 meters/second (the Vaavud is Danish, hence the metric measurements and strange name), can share recorded data with the world through its free app—and it’s been tested for accuracy in a wind tunnel.

But the real stunner about the Vaavud is that it doesn’t use Bluetooth, Wi-Fi or any other power-draining wireless radio to connect. Instead, it uses magnets.

Most smartphones have a magnetometer, so the phone’s digital compass can tell which direction you’re facing. The Vaavud’s designers figured out how to tap into that sensor by hiding two small magnets inside the wind sensor’s rotors. When the rotors spin, the magnetometer senses the speed and voila, a wind-speed reading appears on the screen. Insanely brilliant.

While theoretically any phone with a magnetometer should be compatible with the Vaavud, it’s only been tested and calibrated with the most common models: the iPhone 4/s/5, iPads 2 and 3 and the Samsung Galaxy S2 and S3.

You can get one starting today for $45 at BiteMyApple.

• SourceVaavud