Sensible Products Refrigerant Leak Repair Sealant: Fractional to 1.5-5 Tons Systems, Injector SystemThe Fastest, Easiest Refrigerant Leak Sealant! Introducing Insta Seal IS L, the lightning fast sealant that quickly seals refrigerant leaks. Its innovative injectable design is easy to use and provides a long lasting seal compatible with 1. 5 to 5 ton HVAC units. Its injection method makes it easier to install than other sealants. Pumping down the unit is now a thing of the past. Compatible with all refrigerants (excluding ammonia). No more large