Ultra compact micro-design is small in size and big in features. Unit measures air velocity in five user selectable values: meters per second, feet per second, miles per hour, kilometers per hour, and knots. It also displays: maximum airflow measured, temperature in °F and °C, and wind chill temperature in °F and °C. Measurements are lightning fast with reading updates 2 times per second. Simple one-button operation eliminates the need to refer to directions. Tough ABS plastic housing and water- resistant design keeps out moisture, dust, and dirt, assuring a long life in severe lab, harsh plant or outdoor environments. High contrast LCD digits are over 3/8-inch-high and easy to read. Electro-luminescent backlight allows the display to be read in total darkness. To assure accuracy an individually serial-numbered Traceable® Certificate is provided from the manufacturer's ISO 17025 calibration laboratory accredited by A2LA. It indicates traceability to standards provided by NIST (National Institute of Standards and Technology). Rugged ABS plastic case is 1-3/4 x 4 x 5/8 inches; weight is 1 ounce. Supplied with a Traceable® Certificate, lanyard, nylon carrying case, and long-life lithium battery. Replacement battery Cat. No. CON1005.