The Sentinel X100 Central Heating Scale Inhibitor is a 1 Liter solution specifically designed to prevent scale build-up in central heating systems, specifically in boilers. The inhibitor, made by the brand Sentinel, helps to protect the system by reducing the risk of corrosion and increasing the efficiency of the heating system. This clear solution is effective in maintaining the optimal performance and longevity of central heating systems by keeping them free from harmful scale deposits.