The Duramax LB7 Injector Puller kit is designed to work on 2001 to 2004 LB7 Duramax Diesel engines. Over time carbon forms around the injector tip ans sleeve. Factory pullers pull at and angle causing the injector to bind in the sleeve. This partially pulls or loosens the injector sleeve leaving the sleeve in the head requiring additional service procedures. The Schley injector puller pulls straight removing the injector and sleeve as an assembly. This reduces the potential of having to perform a second service procedure to remove the sleeve. After the injector / sleeve assembly is removed use the injector / sleeve separator to safely remove the sleeve from the injector. Warning: This product can expose you to chemicals which is [are] known to the State of California to cause cancer and birth defects or other reproductive harm.