Frequency tachometer 1.Easy to read, high resolution 2. 4 digit display 3. Sampling rate abt: 0.5 times/ DP4-FR1 Series Digital Frequency TachometerMain Features:1.Dimension: 48H x 96W x 112L mm2.Widely used in the field of measuring speed, frequency, linespeed,3.LED display, easy to read the value.4.High accuracy , good performance5.Input signal level: 3~30V6.Power supply: 220V AC