Adjustable post wall mount systems use a post cantilever single arm of 14", 18" or 24" with appropriate wire shelves and posts. Two post cantilever single arms and 4 post mount brackets are included per order. Post Cantilever Double Arm is available in 14", 18" and 24" and uses the center post for continuous or add-on shelf sections. One post cantilever double arm and 2 post mount brackets are included per order.