Pocket sized anemometer with 14mm LCD display.Data hold freezes displayed readings.Measurement units: m/sec, ft/min, mph, km/hr, knots or Beaufort force.Provides highly accurate air velocity readings: 0.4 to 40m/sec.Dust-tight and waterproof to 1m to IP-67 (IEC standard 60529) .Can be submerged for up to 30 minutes. Designed to float, perfect for use in industry and recreation industries, wet environments, over water or in wet weather. High precision Zytel bearings and a light weight impeller. Shock-resistant.Typical battery life approx 300 hours. Auto power off after 45 minutes of no activity.Supplied with lanyard and battery.