UT370 series photoelectric digital tachometer is of stable performance, safe and reliable. The device circuit design takes the single chip as the core. The photoelectric revolving speed sampling & processing and unique appearance design make the device become the tachometer with excellent performance. The tachometer can be used for revolving speed measurement and count. Specifications: Range : Best Accuracy Mode l: UT371 RPM Range : 10RPM～99RPM ±(0.03%) 100RPM～999RPM ±(0.04%＋2) 1000RPM～9999RPM ±(0.04%＋2) 10000RPM～99999RPM ±(0.04%＋2) Counts : Range: 0～99999 √ : Max.Input Frequency : 10KHz, Bandwidth: 5% Target Distance : 50mm～200mm  √ Features: Display Count : 99999 Data Hold : √ Auto Power Off : Around 15 minutes √ Low Battery Indication : ≤4.8V √ MAX Mode : √ MIN Mode : √ AVG Mode: √ General Characteristics: Power: 1.5V Alkaline Batteries (LR6)X 4 LCD Size : 53mm X 41mm Product Color: Red and Grey Product Net Weight: 100g Product Size : 184mm X 56mm X 34mm