Premium, 12 oz. R-134a A/C Recharge Kit with SMART CLIPS. Smart Clip Technology - Easy to use vent clips change to blue and green to show correct refrigerant Blaster 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. Push-Button disposable recharge hose. Not for use on hybrid/electric vehicles with non-belt driven (electric driven) compressor.