Change out all your standard o-rings on a cornelius keg with this o-ring replacement set! This comes with one center closure o-ring, two post o-rings, and two dip tube o-rings. These are all the standard o-rings that come on a Cornelius keg. Change these out periodically, when your connections get hard to make or when your o-rings begin to fray. Always handy to have on hand in case of a kegging emergency!