... 3.quick and easy to operate BD503 Handheld Optical Power MeterDescriptions BD503 Handheld Optical Power Meter is a self developed test instrument which is ... LC,MU can be optional )Measurement Range(dBm)-70~+10-50~+26Uncertainty±5%Standard Wavelength(nm)850,1300,1310,1490,1550 ... ,ST interchangeable connector ,battery, carry bag, user’s guide. Optical Power Meter,Fiber Power Meter,Optical Power Detector