Use the provided S-Hooks to attach the Wire Shelving Add-On to your existing unit at a right angle to make a corner shelving design or to the end to extend the lengths of your shelves. 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 Made for indoor use, dry storage only 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.