This DIY air conditioning recharge kit from AirconTopup.com is designed for fast and easy use, potentially filling an empty system or being used for multiple cars. Made in the USA, it is compatible with original refrigerant and comes with instructions. You receive 3 x 168g refills, equivalent to 1359g of R134a. Please ensure you use a hose compatible with our can system (1/2 inch coarse right hand ACME thread). The engine and AC compressor must be running and switched on before adding the product. Once attached, the can must not be detached until empty as it may still contain pressure. Returns are not accepted on deployed/pierced cans. This product is suitable for competent DIY users; read instructions before use and contact us for assistance if needed. It is ozone friendly and does not require an F Gas license. Our cans are sized for an average car's depleted coolant level, though larger systems may require more than one can. Refer to vehicle data or use a gauge/weights for correct filling.