Function: 1 Using microcomputer technology, photoelectric technology. Measuring range of 60‑40000RPM / FPM provides high precision digital reading. 2. Large screen LCD display with backlight, digital control to adjust the power of the flash frequency, the maximum display is 40,000 and provides accurate RPM measurement. 3 Advanced technology such as anti-interference technology allows you to measure the rate of contactless and detect the condition of moving objects and defects. 4 It has a wide range of applications and can be used to measure motors, mechanical parts, lathes, etc. For general industrial maintenance, production, quality control, laboratory and school. 5 The shell is made of high quality ABS material, durable, durable, lightweight and long lasting. The entire design is carefully designed to hold comfortably in any hand. How to use: load the battery into it. For the device, press the READ, align the object to test. (For specific operations, please follow the instructions) Specifications: Item Type: Tachometer Material: ABS Color: As shown in the picture Model: DT2240B Battery: 1.5V AAx4(not included) Application: Can be used to measure the motor. Mechanical parts, lathe, etc. Measurement Range: 60-4000 RPM / FPM Speed: R / min FPM: F / Minute Coarse Adjustment / Fine Adjustment Range Less than 1000 RPM, Coarse Adjustment: 10 RPM / FPM Fine Adjustment: 0.1 RPM / FPM ≥1000 rpm Coarse Adjustment: 1 RPM / FPM Accuracy: 0.05% Resolution: