Omnipure ® K2533 2" X 6" GAC Inline Replacement Water Filter With Quick Connect Fittings. 50 per case, sold individually. Note: The connectors come with a "plug" in them for sanitary reasons. This keeps dirt and debris from entering the connector prior to use. To remove the plugs you push in on them and hold down the outer plastic ring, and then pull the plug out. The same method is used to remove the tubing when it comes time to replace the filter. 25 per case, sold individually. Order a case and save even more.