The built-in stacking ribs are designed to inhibit root swirling and the square band corners promote root growth better than round pots. The open cross-bottom air prunes roots growing out the bottom of the container. Bands hold more soil than round pots in an equivalent space. Don’t accept anything less. Our Bands are proven by many years successful use in greenhouses and by nursery propagators. All our Bands are reusable year after year.