As our most popular depth, these are the top-selling wire shelving add-on kits! This convenient storage solution extends existing wire shelving end-to-end or at a right angle, maximizing floor space in crowded warehouses, offices, and even kitchens. Simply attach two S-Hooks on each shelf (included) to join your starter unit to the new add-on unit. And to add versatility and increase mobility, browse our wide range of compatible wire shelving accessories.