Eheim's sealing gasket makes a watertight seal in between your tank's main motor head and filter body. This rubber seal ring prevents water and pressure leaks, keeping your motor system running at its most efficient capability. Improper sealing can lead to flooding and ineffective motor function.
Timely maintenance is important to extend your motor's life. Be sure to check the condition of the main seal ring every time you do filter maintenance. If it isn't sealing correctly, appears stretched out or has other noticeable wear and tear, replace gasket immediately.