This type of Handheld optical meter is a compact and an easy-to- testing instrument for optical fiber networks, which can be used for absolute optical measurements as as for relative loss measurements in optical fibers. 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, calibration 48 hours super long standby time; simple interface ; support //st interface; working hour over 8 hours without charging. Material:plastic colour:blue Package Contents: 1 x Optical Meter(Without battery) 1 x Connector 1 x Connector Only the above package content, other products are not included. Note: Light and different displays may the color of the item in the a little different from the real thing. The measurement allowed error is +/- 1-3cm.