Inside Cover These repair parts are replacement cover assemblies or components for a toilet's automatic flush-valve. The cover houses the sensor mechanism at the top of the flush valve to shield the sensor from damage while allowing it to detect nearby users. These parts include assemblies with a cover, ring, and sensor for making a full replacement as well as components for replacing individual parts of a cover assembly. They're used as replacements for cracked or clouded covers that no longer protect the sensor or allow it to function properly.