La Marzocco has a uniquely designed portafilter spout that snaps onto your portafilter and is held in place by rubber o-rings. Once you have had your La Marzocco machine for some time, it is unavoidable that certain parts will begin to wear and perish. We don't usually spend too much time thinking about small rubber o-rings, but they are something you don't want to get caught without. Buy your replacement o-rings here.