GEARWRENCH 2967 Hand-Held Tachometer
Features: Tachometer checks diesels, pumps, compressors, power take-offs and farm and construction equipment revolution speed. Tool is ideal where electric tachometer cannot be used. To use, hold rubber tip against end of rotating shaft and read revolutions per minute directly from dial. Range is 100 to 4000 rpm (clockwise or counterclockwise). Length: 4-1/4". Diameter dial: 2-3/4".