There are many wonderful rack systems available. Here are some reasons why Vision racks are among the best in my opinion:
1. On wheels
2. Extremely sturdy, yet, you can disassemble it if needed
3. You can add/remove slots as desired
4. Boxes slide easily
5. Heating (with heat cable) is adjustable - you can run more cable on some shelves compared to others, making housing species with different heat requirements possible in a single rack. (Was that clear?)
6. Shelves are plastic and have ridges underneath for rigidity (no bowing).
7. Open air on all sides allows for better ventilation.
8. Visions's V-series boxes (if you get these) are smooth on the inside and inside corners, plus they are a bit thicker than Sterilite or Rubbermaid or Iris.
I tell you this as a hobbyist who appreciates functional equipment for keeping snakes.
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Mark