Red Angel  A/C Stop Leak - 2 Ounce (49496) Remarkable ability to repair and seal leaks in condensers, evaporators, connection hoses, gaskets, and O-rings Contains no solid or particulate matter that will clog the A/C system, or harm a recovery unit Forms a chemical weld sealing leaks in both R-12 or R-134a systems Safe to use It's a permanent seal