Crow, I had to replace 1 and used the daystar brand. It seems to have sealed ok. It is just kinda wierd when you put them on. You expect them to go around like the rubber ones with a clip but all you have to do is fill it with grease and slip it over the stud and tighten it down. That is what I was told by the Daystar guy and so far like I said it looks OK. HTH Jim