RO Drain Saddle Assembly The RO Drain Saddle Assembly is used to connect the waste line from a reverse osmosis system directly to a drain pipe. Drain Connection for RO Waste Water This saddle assembly helps create a cleaner RO/DI installation by eliminating the need to run the waste water hose loosely into a sink or drain opening. Drain Saddle Features Connects an RO waste line to a household drain pipe. Useful for permanent or semi-permanent RO/DI installations. Helps keep the waste line organized and secured. Commonly used under sinks or near RO/DI filter mounting locations. Directions Install on a suitable drain pipe following the RO unit layout and local plumbing requirements. Drill the drain line opening only after the saddle is positioned correctly, then connect the RO waste tubing and check for leaks during operation. What's Included 1 RO Drain Saddle Assembly.