16357 Robinair Dye Cartridges, Qty-6.  Six 1/4 oz. 7.5 ml twist-on cartridges. Enough dye for six applications (OEM-approved and SAE-certified dye). Simple to use: Twist a cartridge onto the injector gun, hook up to the service port, and pull the trigger to inject the dye into the A/C system. Put your old lamp to use to spot the leak and you’re done.