Sloan Part 3325456 EBV-145-A Inside Cover Assembly with Solenoid

Sloan OEM part. This solenoid and metal bottom plate sit under the the electronic control box inside the cover of the flushometer sensor assembly. They control the water bypass chamber which in turn controls the flush diaphragm. If your toilet flushometer is not allowing enough (or any) water through when the sensor is tripped, and you've checked the batteries, and the diaphragm, this is the next most likely cause.