-Aerosol -Forms a hard seal on metal, schrader valves, o’rings, gaskets, a/c condensers, evaporators, line sets and solder joints -Enviro-Safe Proseal XL4 repairs minor leaks in home, heat pump, large auto, and industrial applications -One can will normally repair a leak in systems up from 1.5 to 5 ton. If you have a smaller unit, please contact us. -If the a/c system that will not hold a vacuum, you need to use the Enviro-Safe Prodry XL4. -The reason for the vacuum or the use of Enviro-Safe Prodry XL4 is that it will eliminate moisture in the system. Moisture mixing with oils and refrigerant can cause you system to make sulfuric acid which will corrode and eat your system! -For larger units over 5 tons, we suggest you use the Enviro-Safe Proseal XL4 Direct Inject. These are available in various of the larger sizes. -Even though Proseal XL4 can form a seal on the schrader valve, when you hook up to it the seal will release and allow you to use the schrader if necessary. If there is still Proseal XL4 in the system it will reseal the schrader. -DO NOT use in ammonia systems -DO NOT use in CO2 systems -DO NOT use in R410a systems- Pressure is too high and will explode the can- You MUST use the Enviro-Safe Proseal XL4 Direct Inject line of products. -Cannot be sent to Alaska or Hawaii or exported to foreign countries except in pallet quantities -Gas propelled -Installs the same way as refrigerant -Cannot be added to a fully charged system Must be shipped to a physical address. We will not ship to P.O. boxes. This is ideal for sealing leaks in home and industrial units.