Current / Average (5, 10, 13, seconds) / Maximum wind speed; Mph, Knots, Kp/h, BF, ft/min, m/sec; Optional wind tunnel accessory and tripod fitting; Replaceable Lithium battery CR2032; Digital wind direction in degrees and compass points; Temperature in F or C plus Windchill; Digital compass accuracy +/- 2? ;Wind speed accuracy +/- 3%;Temp accuracy +/- 1.8? F; Size 5.5 x 1.75 x .75 / Weight 3.20z