Linear current booster trades excess incoming voltage to boost outgoing current. For Shurflo 9300 solar direct applicaitons. 7 amp model for use with 7 amps or less of PV input. Panel voltage: minimum 16 volts for 12 volt applications; minimum 32 volts for 24 volt applications. Comes with a float switch contact. Allows use of float switch up to 2000' away with 18 gauge wire.