Hall wind meter in km/h. Measures up to 100km/h in increments of 20km/h beginning at 20km/h. Hands down the best kind of wind meter for paragliding/hang gliding or speed flying, super durable, accurate, never runs out of batteries and lasts for decades. The floating indicator also gives you an unbeatable visual impression of the amount of turbulence in the air simply by watching the way it moves. Large quick deviations greater than 10km/k in a 10sec period indicate rough conditions. I've had mine for 20 years - still going strong.