Power Requirement:dc 8-24v Measure Range:10 ~ 9999rpm. Error Range: 0. Clear Zero:automatic . Clear Zero Time:about 10s. Refresh Frequency: 0.2-0.5s(120-1200rpm),0.25-0.06s(2400-9999rpm). Response Frequency:100hz. Measure Indication:(rpm Less Than 5000,2),(rpm Greater Than 5000,3). Sign:npn 5 Wires Normally Open. Display: 4 Red Led. Tachometer Size:79 X 42 X 25mm. Panel Cutout Size:76 X 39mm. Hall Proximity Model:njk-5002c . Detected Objects: Magnet. Detection Range: 1mm-10mm. Proximity Output Current: 20ma(for The Sensor). Operating Temperature: -10 To 60c. Sensor Wiring:brown(power+),black(test+),blue(signal). Sensor Size: 60 X 10mm. Sensor Wire Length:1.2m Magnet:10x2mm Function Selection: 1.reset Or Manual Reset On Power. 2.store The Data (no Power). Material:metal+plastic Package Include: 1 X Red Led Tachometer 1 X Npn Hall Proximity Sensor 1 X Magnet Note:light Shooting And Different Displays May Cause The Color Of The Item In The Picture A Little Different From The Real Thing.the Meas