What is the difference between Sentinel X300 System Cleaner and Sentinel X400 System Restorer?

Sentinel X300 System Cleaner is used to prepare new closed loop hydronic heating systems (6 months old or less) for treatment with inhibitor to prevent future corrosion and limescale build up. Sentinel X400 System Restorer is used to revitalize closed loop hydronic heating systems older than 6 months which are suffering with issues related to limescale and corrosion debris build up.