... and IC-counter,intelligent,wide range,multifunction,highbright 8 digit LEDs display. Measurement functions:frequency:A,B,C, Period:A,B, Count:A,B,A+B ... ,A-B,A/B,A→B and intenal frequency.A,B with attenuators and LPF.2.2 ... power IC LM3886TF,has protection of overtemperature,overvoltage and short-circuit,input and gain adjustable,INT/EXT speaker.5.2 ...