Perfect-Prime TA0522 Contact/Non Contact Digital LCD Laser Photo Tachometer RPM Motor Speed Gauge 2 in 1 Accuracy:+/- (0.02%) + 2 digit Contact Measurement Range:2~ 20,000 RPM Non Contact Measurement Range:2~ 99,999 RPM Measurement Distance:50mm ~ 600mm Battery: 9V DC (not included)