Digital Contact Tachometer DT2235A contact tach:0.5-19,999 rpm, surface speed:0.05-1,999.9m/min Digital Contact TachometerModel: DT2235AShenzhen Sanpo Instrument ... Quartz crystalTime Base Accuracy: 10x10-6(0~50°C)Measurement: CONTACT TACH: 0.5~19,999RPM SURFACE SPEED: 0.05~1 ... ,999,9m/min SURFACE SPEED: 0.2~6,560ft/minResolution:CONTACT TACH:0.1RPM(0.5~999.9RPM)1RPM(over 1 ...