These AEM Electronics water/methanol injector nozzle kits are typically used to add a second injector to an existing system. They are CNC-machined from 6061-T6 billet aluminum and then hard anodized in black and laser-etched with the AEM logo. The injector kits also come with an integrated check valve, one of each sized nozzle (0.0315 in., and 0.0630 in.), a T-fitting with quick-connect ends, and a 4 ft. section of 1/4 in. diameter nylon hose for easy attachment.