Pre-wired for quicker installation. Can be set up in concentration, probeless or auto switchover mode. In auto switchover mode, Titan II automatically switches to probeless mode if the probe fails to function correctly. Once the condition is resolved, it will switch back to concentration mode and log the switchover eliminating the need for an emergency service call. Spring loaded 2-roller design for extended tubing life. No tool quick change squeeze tube and quick connect fittings.