Black Wire Shelving Add-On kit allows you to expand your Starter kit by sharing a set of posts. Configuration options include straight line, back to back and right angles (L-Shape). Add-On kits come complete with 2 posts, 5 shelves and 16 S-Hooks. Additional shelves may be purchased separately. Units with Add-On kit cannot be made mobile. Includes 2- 74" Posts, 5- 24" x 24" Black Wire Shelves and 16 S-hooks