Fernox Central Heating Leak Sealer F4 Express 400ml Quick and convenient doses in 30 seconds Simple to use with no mess Added via a radiator adapter or filling loop supplied Non-toxic, environmentally friendly formulation 100% recyclable can Seeks out and seals most weeps and leaks Saves time and money on draining down and repairing Does not cause blockages of pumps, air vents, etc Compatible with all Fernox Protectors Due to geographical locations we are unable to deliver to: Isle of Wight, Isle of Man and Ireland.