Our Chrome Wire Shelving Post Clamps are simple and creative hardware pieces you can use to secure two wire shelving units together for extra stability and strength. Each pack comes with two sets (four pieces) and screws Secures two separate units by clamping two 1" round posts together For a stronger hold, purchase four sets to clamp the top and bottom of the units together Use a post clamp on the top and bottom for maximum stability on units 72"h or taller FREE SHIPPING.Ships Next Business Day.