The Microline S7029 is a replacement sump for Microline Clack Reverse Osmosis (RO) system manifolds. Over time, normal wear and tear can cause deterioration to your old sumps. If you notice water leaks coming from your unit, check the o-rings and inspect the sumps as well. Replace the sump if it appears damaged. You can repair your RO unit with a new sump, without a complete system overhaul!