Listing for a full pack of 10!!! Enhance the efficiency of your central heating system with the Fernox F1 Protector. This multipack of 10 units is ideal for storage tank water heaters and boilers. Made in the United Kingdom by Fernox, a trusted brand in the heating industry, this product is perfect for extending the life of your heating system and ensuring optimal performance. The Fernox F1 Protector is a great addition to any home or commercial heating system. Its 500ml capacity is perfect for inhibiting corrosion and sludge build-up, which can lead to costly repairs. This unit is easy to instal and is suitable for use with a range of heating systems. Get your hands on this high-quality product today and enjoy a more efficient and reliable heating system.