Tracer Spectronics Corp TP98700601 EZ-Ject Multi-Dose Cartridges for A/C and R Systems Disposable cartridges come pre-filled with enough dye to treat 14 or more standard-sized vehicle A/C systems The EZ-Ject assembly (plunger handle and fitting), dye cartridge and hose with quick coupler easily connect to a vehicle's A/C system Service multiple systems 6-1.5 oz cartridges Great for diagnostics, too. Nothing is easier!