The OTC Injector Seal Installer and Sizer Adapters, No. 6757, installs the Teflon seal onto the end of the injector. The pilot cone is placed onto the end of the injector and the seal is started over the cone. The installer then pushes the seal into the groove on the injector tip. The sizer goes over the seal to compress it back to the correct OD to allow installation into the cylinder head. For use on 1998 to 2014 GM engines with SIDI single seal injectors.