The sensor suite is a ship fitting of sensors on an antenna mast, wired through circuits and built in an Assembler. It adds to the sensors of the ship that carries it, so the ship makes out more about other ships in its system. With enough suites, the ship's sensors reach into the systems one jump away.
It is a small fitting for a slot, not a hardpoint. It is fitted and removed at a station with a shipyard in the ship's system.