Get the most out of your existing shelving unit by expanding it as your storage needs grow. Attaches to existing chrome wire shelving units for additional storage space Stores up to 800 lbs per shelf, evenly distributed Shelves adjust every 1" along posts S-Hook 2-Packrequired per extra shelf To securely set or quickly remove shelves, tap their corners with arubber mallet. View ourWire Shelving Size Guideto see actual outer and inner dimensions.