AFL's OPM4 optical power meter is a handheld instrument for measuring optical power and insertion loss in multimode and single-mode fiber networks. The OPM4-3D variant uses an InGaAs detector and is calibrated at 850, 1300, 1310, 1490, 1550 and 1625 nm, with a measurement range of +10 to -75 dBm. The OPM4 series supports Wave ID automatic wavelength identification, tone detection, reference storage per wavelength, field-swappable connector adapters (connector/adapters sold separately), long battery life from AA cells, and N.I.S.T. traceability.