The Fluke Fiber Optic Meter (FOM) helps you test and maintain fiber optic cable without having to buy a whole new meter. Plug the FOM directly into any DMM with a mV dc function and a 10 M? input impedance and quickly and accurately verify fiber optic cable system loss. Light sources and patch cords sold separately. Specifications Weight 5.0 oz (142g) Storage temperature -20" C to +70"C Operating temperature 0" C to +40"C Display Resolution 0.01 dB (0.001 "W) Dimensions 4.5 x 2.5 x 1.5 in (11.4 x 6.4 x 3.8 cm) Measurement Accuracy "0.25 dB at -10.0 dBm and 25"C Calibrated Wavelengths 850 nm, 1300 nm (used also for 1310 nm), and 1550 nm Dynamic Range +3 to -50 dBm Detector Type Germanium