This type of handheld optical power meter is a compact and an easy-to-use testing instrument for optical fiber networks, which can be used for absolute optical power measurements as well as for relative loss measurements in optical fibers. Features: Accurately measure the network sequence and judge the signal transmission. Portable and light weight for easy carrying. With a LED light for dark environment operation. After switching wavelengths, switch on the machine and keep the same wavelength as before the last shutdown. Backlight function, dark environment can see the screen. External soft rubber cladding for fall and collision preventions. Specifications: Power test range: Type A -70 to 10dBm, Type B -50 to 26dBm (optional) Color: white+black Wavelength range: 800-1700nm Accurancy: ±5％ Standard wavelength: 850nm/980nm/1270nm/1300nm/1310nm/1490nm/1550nm/1577nm/1625nm/1650nm Display resolution: linear display 0.1%, logarithmic display 0.01dBm Identified frequencies: 270Hz, 300Hz, 1kHz, 2kHz Automatic shutdown time: 10min Battery: 2 * AA battery, 3.7V, 700mAh (not included) Item size: 120 * 71 * 28mm / 4.7 * 2.8 * 1.1in Item weight: 130g / 4.6ounce Package size: 130 * 85 * 33mm / 5.1 * 3.3 * 1.3in Package weight: 280g / 9.9ounce Packing List: 1 * Optical Power Meter 1 * English User Manual 1 * Chinese User Manual 2 * AA Battery 1 * Rope