PETROMARK® 10410 RADIATOR SEALER water-based and consists of natural resinous fibres, stabilizers and anti-corrosion additives in suspension. Recommended for sealing off leaks in radiators, heaters, cylinder heads and engine block cracks up to 0,9mm wide. Works quickly, permanently and reliably and cause no obstructions. Miscible with all types of anti-freeze and cooling liquids. Does not damage hoses, gaskets or metals. Suitable for cooling systems with a capacity of no more than 12 litres. By adding this product preventively to the cooling system it affords comprehensive leakage protection and guarantees a trouble free working system. Instructions for use: Shake canister well before use and add the content of the can to the cooling system when warm, with the engine running and with the cabin heating switched on. Keep engine running for approx. 10 minutes or drive a short distance. Dirty cooling systems should first be cleaned with PETROMARK® 10412 RADIATOR FLUSH.