Simple and compact, the Kestrel 1000 Handheld Wind Meter fits right in the palm of your hand and weighs a mere 2.29 ounces (65 grams). It's also extremely durable and completely waterproof, allowing you to measure wind speeds even in the harshest weather conditions. The Kestrel 1000 can easily be switched between mph, km/h, ft/min, m/s, knots and Beaufort. Convenient and reliable, the Kestrel 1000 is the perfect tool for model plane pilots, kite boarders, and other outdoor enthusiasts who rely on accurate wind speed information. The Kestrel 1000 is the most common handheld wind instrument for a DZSO (Drop Zone Safety Officer). A hard slide-on protective case, lanyard, and lithium battery are included. Protective cover with sure-grip overmolding Data hold function Large easy-to-read display Waterproof Patented user-replaceable impeller Wide range of wind speeds and low startup speed Reliable, portable, and easy to use All instruments and accessories are completely assembled in the USA Winds can be measured on any Kestrel up to 135 mph. NK only guarantees the accuracy of the measurement to be within tolerance up to 89 mph. Also at those speeds, it is not recommend any prolonged exposure as it could damage the impeller at those speeds for any prolonged length of time. It is similar to being able to measure very hot temperatures outside of the spec range but do not do it for any extended time.