Fernox Central Heating Protector F1 500ml Option:500ml For wood and metal Progressive tooth For wood and metal Progressive tooth strip for high cutting performance and fast chip clearance HSS bi metal with 8% cobalt alloy for extreme resilience and a long lifetime Power change adapter for fast and safe attachment and release fitting both left and right hinged inward or outward opening doors Hardened steel rollers in bolt Interior & Exterior Material: Steel & Zinc Alloy Fixings included 5 year guarantee and warranty environmentally friendly Protects against corrosion and scale in mixed metal central heating systems When used in conjunction with Cleaner F3 gas savings of up to 15% can be achieved every time you heat your room Stops frequent venting of radiators Prevents sticking pumps and boiler noise Reduces maintenance costs and saves on fuel bills Prevents cold spots in radiators Non toxic