It is easy to operate. The handheld design is more compact, easy to carry and can be measured. Short blind zone (15rn), high-speed signal processing, short test time and quick analysis. It can store 10,000 waveforms, and the LCD screen has a higher contrast color. The quality of the waveform can be improved, the USB terminal shape is more, and the IF D LCD screen has a higher contrast color. The quality of the waveform can be improved, and the USB port can be connected to a computer. With input laser signal automatic detection and self-protection function, built-in red light source, humanized OTDR anti-reality software shows the details of the event.