Boot kits seal a joint in the car that would be destroyed by dirt, sand and other particles if left exposed, even under normal conditions so it's important that they be properly maintained and in good condition. When it is time for a replacement, the Rein Boot Kit program offers application specific inner and outer axle boot kits complete with everything needed to do a proper installation. These kits even come with OE grease and all the hardwar needed for a guaranteed fit the first time.