1、It can be accurately measured without touching object with high accuracy. 2、It features automatic power off control without operation within 15min to keep safety, you don't worry if you forget to turn it off. 3、When the voltage is above 4.8V, you will be prompted to guarantee the long service life. 4、It is applicable to schools, factories, environmental protection bureaus, laboratories, research institutes, automobile maintenance testing and other fields. 5、The measuring range of rotational speed of this product can be as low as 10RPM and as high as 99999RPM to meet general needs. 6、The circuit design of the whole machine is based on single chip microcomputer and adopts photoelectric rotational speed sampling processing. Condition: 100% Brand New Item Type: Tachometer Material: ABS Optional Type: UT371, UT372 Basic Function Range Basic Accuracy Model UT371 UT372 Rotational Speed Measurement（RPM） 10RPM～99RPM ±(0.03%） ±(0.03%） 100RPM～999RPM ±(0.04%＋2） ±(0.04%＋2） 1000RPM～9999RPM ±(0.04%＋2） ±(0.04%＋2） 10000RPM～99999RPM ±(0.04%＋2） ±(0.04%＋2） Count Range: 0～99999 √ √ Maximum Input Frequency：10KHz,Pulse Width 5% Object Distance 50mm ～200mm √ √ Special Function Maximum Display 99999 99999 Data Hold √ √ Auto Power -Off About 15min √ √ Low Voltage Display ≤4.8V √ √ Maximum √ √ Minimum √ √ Average Value √ √ USB Data Transmission √ General Features Power 1.5V Alkaline Battery（AA）× 4 (not included） LCD Size 53x41mm/ 2.1x1.6in Color Red+Grey 1 x Tachometer 1 x Data Cable 1 x Reflective Sheet 1 x Instruction