Blaster's proprietary refrigerant formula replaces lost refrigerant and oil. The formula improves the A/C's cooling capabilities and provides better heat exchange by forming a protective film to decrease friction, reduce engine drag, prevent oxidation and sludge formation and extend the compressor life. Stop Leaks system safe chemical additive stops leaks in o-rings and other rubber components where most common leaks begin. Increases system performance Not for use on hybrid/electric vehicles with non-belt driven electrivc driven compressor Used for truck and auto Includes UV dye for leak detection under UV light Includes 1 oz of R-134a refrigerant gas to seamlessly blend within system Can be used to proactively protect AC system from leaks