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. Telecom Maintenance,CCTV Maintenance; Comprehensive cable construction system,Optical instruments research and development; Optical communication education and lab testing; Other optical project Supports 6 wavelength Testing, Auto-off function, with Backlight, self calibration 48 hours super long standby time; simple interface ; support sc//st interface; working hour over 8 hours without charging. Material:plastic colour:blue Package Contents: 1 x Optical Power Meter(Without battery) 1 x Connector 1 x SC Connector Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.