The lid on most Brita pitchers is held on by a pretty thin piece of plastic, which snaps quite readily if dropped the wrong way. No lid would be tolerable, except for the fact that it makes the filter usage sensor stop working properly - it appears to be based on a light sensor, detecting the number of times you open the lid to fill the reservoir.

This is a simple replacement for any snapped-off lids. The L-shaped piece provides surface area for some superglue to bond with part of the opening mechanism; this does mean the lid can't open fully, although it's enough for my faucet to fit handily. Your mileage may vary.