The Nu-Calgon 4050-10 A/C EasySeal XL is designed to prevent as well as repair leaks anywhere in the system, including condensers, evaporators, copper lines, and soldered joints. It is easily injected into the system, traveling with the refrigerant, searching for leaks. It circulates through the system with the refrigerant seeking out leaks rather than migrating slowly with the oil…keeping in mind that only a small portion of the system oil actually migrates with the refrigerant through the system. A/C EasySeal XL will react with moisture or air that is naturally present at a leak, forming a secure seal. It is compatible with the refrigerant, oil and all system materials and it will not react until it comes into contact with the air and moisture at the leak, forming a permanent seal. A/C EasySeal XL is a time saver. It finds leaks quickly and seals them, saving the time and money required in searching for the smallest leaks. With A/C EasySeal XL, the contractor is able to just add a can to the system and be confident the leak has been fixed and move on to the next job. In most cases, one can will seal systems that have lost all refrigerant in as little as seven days and is designed for large systems up to 5 tons. THE NU-CALGON 4050-10 A/C EASYSEAL XL IS FOR PROFESSIONAL USE AND SHOULD ONLY BE USED IN ACCORDANCE WITH ALL REGULATIONS AND PROPER SERVICE PRACTICES. PLEASE SEE PRODUCT LABEL OR CONTACT NU-CALGON DIRECTLY FOR USE INSTRUCTION. IT IS RECOMMENDED TO UTILIZE THE APPROPRIETE PPE (PERSONAL PROTECTIVE EQUIPMENT) DURING APPLICATION.