This is the guts of the shutoff valve for the toilet in our 1/2 bath. The black thing on the bottom is the rubber washer that interrupts the flow of water. But it’s from (guessing) 1987 and so barely qualifies as rubber anymore. It broke into the two pieces you see here, causing two problems: 1. the smaller piece broke off and wedged itself in the tank’s intake valve, causing the toilet to fill very noisily and slowly, and 2. the larger piece, not being whole anymore, was ineffective at shutting off the water, making it hard to fix (1). An easy fix, but required shutting off water to the whole house.
