The shelves slide back and forth, so you can click them into place around the pipe or garbage disposal, using as many or as few as you need. They make more of the under-sink area usable space, since you aren't limited to setting things on the bottom of the cabinet.
And if you have a few tall bottles, you can move the upper shelves to make room for them. That's harder to do with a regular, fixed shelf.
• Under the Sink Storage Shelf, $18.99 from Amazon
What do you think? Do you have any other ideas for keeping the under-sink area more organized?
Related: Stacking and Nesting Kitchen Goods
(Image: Made Smart, via This Old House)