Fluke FOM Fiber Optic Power Meter, 9V Alkaline Battery, 0 to 40 Degree C Operating Temperature 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 MO input impedance and quickly and accurately verify fiber optic cable system loss Light sources and patch cords sold separately A variety of light sources and patch cords let you get just what you need for testing different cable types and lengths Highly accurate readings mean less work, less repeated testing