Feature:1. Operation Procedure: The digital tachometer is operated by lightly pressing the TEST button to start the measurement and keeping the distance between them within 500mm.2. Six Digits Display: The digital tachometer's RPM display is a six digit display with a maximum of 999999, and the automatic shutdown is 15 minutes, which can be turned off manually.3. Measurement Effective Distance: The measurement effective distance of our digital tachometer is 50mm500mm, and the sampling time is 0.8 seconds (above 60 rpm).4. Lock the Value: The contact digital tachometer can lock the maximum value, minimum value and realtime value during the measurement. Tap the maximum key to lock the maximum value, tap the maximum key again to lock the minimum value.5. ABS Material: the contact digital tachometer is made of ABS material with excellent craftsmanship, it is good for nice factory, workshop, processing workshop.Specification:Item Type: Digital TachometerModel: TA500BMaterial: ABSRPM Display: Six digits display, maximum 999999Measuring Effective Distance: 50mm-500mmSampling Time: 0.8 seconds (above 60 rpm)Automatic Shutdown: 15 minutes (can be manually shut down)Operating Environment: -10-50, maximum 80% relative humidity, indoor altitude <2000mStorage Environment: -10-50, maximum 70% relative humidity (battery removed)Battery: 1.5V AAA battery x 2 (shipping without battery).Package List:1 x Digital Tachometer4 x Tachometer Head1 x Instruction Manual