VersaChem® Heavy Duty Radiator Stop Leak works faster and stops larger leaks than traditional “liquid stop leaks” and “non-metallic powdered stop leaks”. This advanced formulation contains pure copper particles with special hardening and sealing agents. Quick triple action seeks out leaks, fills and seals them with pure copper. Compared to most "liquid stop leaks" and "non-metallic powder stop leaks" which contain powder, wood, paper and other fibrous materials, plugging holes without hardening. VersaChem® Heavy Duty Radiator Stop Leak mixes with water and antifreeze mixtures. Use one vial forcooling system capacities up to 22 quarts (20.8 ltrs.).