Having replaced our disintegrating Brita pitcher a few years ago, I finally got around to opening a used filter to see what’s inside. Start by cutting off the flexible rim (intended as a seal against the pitcher) to reveal the joint, then pry the lid off:
Stand it upright before getting the lid off, because the filter contains a zillion charcoal granules and two zillion ion-exchange resin beads:
The inside of the lid has mesh screens to keep the innards in place while distributing the raw water:
Similarly, mesh on the bottom drains let the filtered water out:
No surprises, but now we all know what’s in there.