For use in R-134a and R-1234yf systems; Super concentrated dye detects leaks quickly, saving time and money; Added friction modifier and anti-wear additive improves efficiency and reduces wear; Antioxidant stops acid formation and prolongs oil life; Cartridge works exclusively with theSpotgun Jr.™ injection system; Unit Size: 1 oz/30 ml; Max. Applications: 40 vehicles; Quantity: 4