This module is a part of the NetHomeServer. JeeLink Classic is a Arduino compatible programmable radio transmitter/receiver sold by JeeLabs/Digital Smarties.
OpenNetHome has a custom firmware that turns the JeeLink into a generic 433MHz remote control sender. See details about installing JeeLink here: http://opennethome.org/hardware/hardwareinstall-jeelink
This Item connects to a JeeLink transmitter and sends any 433MHz messages from other Items in the system.