JW3109 Optical Light Source Power Meter -50~+26dBm JW3208C Tester Device Fiber Network Optical Light Source Power Meter ,Easy Use

User self calibration function Comfortable LCD display and optional backlight LCD display supports night operation Power measurements in dBm or mw and insertion loss in dB Low battery consumption, more than 240 hours continual operation time for three 1.5V alkaline batteries Optional 10 minutes Auto-off function