... 1.Low battery alarming, 2.Yellow-green back light, 3.Memory the (max ,min ,last )value , 4.Can store 300 testin. ... Tachometer:1.Low battery alarming,2.Yellow-green back light,3. ... the rotate speed used to 2 stokes and 4 strokes,Can set the cylinder in 2,3,4,5,6,8,12 or ... set the impulse of each rotation.Memory the maximum value,minimum value and ...