Features: The display area and the front buttons are very convenient for operation and display of test data. The panel mainly composed of tube, functions, buttons and LED display screen. Function keys are micro-touching keys. Multiple power management and protector. Lithium-battery has overcharge, overdischarge and short circuit protector functions, and built-in intelligent shutdown and low-power shutdown functions. Because the device has high precise and the clamping guide rail and fixed equipment are the same each-time, and can be made into mining model parallel to the guide rail, the measurement result error is small, and the dynamic fluctuation error is small. Mainly used to learn and experience the high-speed data processing capability of the single chip microcomputer, and measure the flight speed of various things. Such as table tennis, badminton, darts, etc. The core components adopt industrial package, with stable characteristics. Package Includes: 1x Meter Specifications: Material: Plastics Working Voltage: DC4.2V Measuring Range: 1-999m/s Battery (built-in): 1x 3.7V Working Environment Temperature: - 10 to 60 Speed Measurement Range: 1-999m/s Energy Measurement Range: 1-800J Weight Input Range: 0.1-10g Speed Record: 40 Groups Kinetic Energy Records: 40 Groups Size: Approx. 130x50x75mm/5.12x1.97x2.95in note: Please allow 1-2cm errors due to manual measurement, make sure that you do not mind before you order. Due to the difference between different monitors, the picture may not reflect the actual color of the item.