Spotgun™ Jr. System Kit (Single-Shot) Injection System, For those who already have a light and want a Professional injection system that offers accuracy as well as managing dye inventory. The Spotgun™ Jr. "Single-Shot" system uses a single application dye cartridge to help control inventory. Up to 6 applications. (6) Universal A/C Dye Cartridges (Services 6 Vehicles), R-12 & R-134a Adapters Included.