FUNCTION -- Used for replacing the fuel injector Teflon O Ring Seals. Installs the dual seals onto the end of the injector to ensure proper injector installation. APPLICATION -- Fits for GM 2.0L & 3.6L engines with Hitachi Fuel Injectors (2010 - 2017), GM 2.0L, 2.5L, 5.3L & 6.2L engines with Bosch,Continental and Delphi Fuel injectors (2012 - 2017), Fits Holden Colorado 7 (2016), Fits Subaru 2.0L & 2.4L turbo engines (2014 - 2019).