Used the microcomputer (CPU) technique, photoelectrical technique and LCD for one instrument combine PHOTO TACH & MOTION & SURFACE MAR.

Large LCD display with backlight; Digital control adjust flash frequence;
Low power consumption
Measure range: 60~19, 999RPM
Coarse/Fine adjust amplitude:
<1, 000RPM Coarse adjust: ± 10RPM
Fine adjust: ± 0.1RPM
≥ 1, 000RPM Coarse adjust: ± 100RPM
Fine adjust: ± 1RPM
Accuracy: ± 0.05%
Resolution: <1, 000RPM: 0.1RPM
≥ 1, 000RPM: 1RPM
Battery: 4x1.5V AA battery

Pls feel free to contact with me to know more details.