You-knee. Say it with us. You-knee. No, we're not talking about some move taught to insipid little debutante chicks in self defense classes. We're talking about UNI, the oldest filter brand around. If your running a foam style filter UNI or not, we strongly urge you to keep it lubed up and this stuff is the money shot. A little lube goes a long way in reducing not only friction but trapping unwanted particles. After all without lube what fun is anything? Seriously.