The Network Backbone Cable is the data communications "pipeline" that runs the length of the boat, and capped at each end with a 120 Ohm Terminator. Available in a variety of lengths up to 25', the backbone is interspersed with T-Connectors for linking to (and data sharing between) all sensors and display devices. The NMEA 2000® network 12 Volt Power Source connects to the boat's 12-volt supply to power devices like the EP-10 Fuel Flow Sensor, LMF-400 Multi-Function Gauge, and LGC-2000 GPS Module. Compatible Sonar/GPS head units are powered separately with their own 12 Volt Power Source wiring. With such an innovative approach, expanding a boat's network to add sensors and/or displays is incredibly easy convenient, and especially affordable with a Lowrance NMEA 2000® system.*Includes: 2 terminating resistors (TR-120M-RD, TR-120F-RD), one T-connector (N2K-T-RD) and one 2' extension cable (N2KEXT-2RD).