4050-11 - EasySeal Ultimate LS/UV Refrigerant Leak Sealant - 2 to 7.5 Tons (with UV dye)Nu Calgon 4050 11 EasySeal Ultimate LS UV Refrigerant Leak Sealant 2 to 7. 5 Tons (with UV dye) The EasySeal line has proven to be the number one trusted leak sealant brand for years, with millions of leaks sealed. Now Nu Calgon has made EasySeal even better with EASYSEAL ULTIMATE the strongest and fastest leak sealant on the market, now with the ability to treat systems up to 10 tons in one application! Features Permanently seals even larger leaks