Feature: 1. 5 digit large-screen LCD display, large and clear 2. Use an ordinary AA Batery, no external power supply, and easy battery replacemen 3. Press the- PAUSE button to pause/count, press the- PAUSE button again, and resume counting 4. Input adopts ordinary contact signal, simple and convenient to select sensor, accurate and reliable counting 5. The highest counting speed: 20 times/second, 1200- times/minute 6. Clear: Panel/external use Sensor doesn'for t included. Technical Parameters: Power supply: 1.5V AA battery (For safe delivery, not included) Counting range: 0---99999 Counting the highest frequency: 20HZ Counting minimum pulse width: 10mS Contact maximum resistance: 10K Contact disconnection minimum resistance: 500K Clear method: panel/external Clear the minimum pulse width: 0.1 seconds Ambient temperature: -5--40C Dimensions: 64x38x38mm Opening size: 61x36 mm How to use: Start counting: Counting terminal input contact signal, the counter starts counting. Pause counting: Press the- PAUSE button to pause the counting; press the- PAUSE button again to resume counting. Clear the panel: Press RESET directly. External clear: clear the external contact of the terminal and clear- it directly. Package include: 1 x Electronic Counter (Not included Battery for safe delivery)