... series Handheld Optical Power Meter are versatile power measurement instruments. RS6201 can offers eight calibrated points: 650nm,785nm,830nm,850nm,980nm,1310nm,1490nm,and 1550nm ... three types of Optical Power Meter, which divided by different measuring range.TypeRS6201ARS6201BRS6201CDetectorSiliconInGaAsWavelengths650,780,850,980,1060nm850,980,1310,1490,1550nmOptical Power Range+3~-70dBm ...