Perfect for ultra-efficient Hybrid and EV R-1234yf AC systems. This high-quality dye fluoresces easily and does not alter the composition of the original compressor oil. This dye is formulated with high dielectric qualities to protect all system components, including electrically driven compressors. OEM approved and used by major carmakers worldwide. (3) 0.25 oz (7 ml) Mini-EZ™ single-dose R-1234yf Hybrid Vehicle A/C dye cartridges, services up to 3 vehicles