This monitor has two components – a small wireless display you can place anywhere inside your home and a sensor unit. Attach the sensor unit to the outside of your electricity meter, and it will send a signal wirelessly (in kilowatt hours and dollars and cents) to the display unit fixed inside your home. The battery indicator lets you know when your battery power is low and a signal indicator lets you know the strength of the Sensor Unit signal. The PowerCost Monitor is programmable for local utility rates, including flat and multi-tiered, and time of use rates, and should be accurate to within 5% of the actual usage. It will work with most North American electromechanical and solid state/digital electric meters for which the optical sensor or rotating disk is not blocked, including smart meter technologies.