The Xantrex CM-R-50 is a digital meter that attaches to the C35, C40, or C60 charge controllers as a remote meter (it does not fit on the front of the charge controller). For a solar array, DC loads, or diversion loads, its back-lit display indicates voltage, amperage, and resettable cumulative amp-hours. For remote installation, this display comes with a 50ft communication cable.