EDSAL Mid-Profile Rivet Lock Shelving combines maximum storage strength with easy assembly! Double rivet construction comes together without bolts, clips, or special tools. Mid-profile Z-beam locks into keyhole slots to provide a strong, flush deck surface. Shelves adjust in 1-1/2" increments. Because no special bracing is required, stored contents are easily accessible from all sides. Choose either 5/8" particleboard or tough 12" wide steel decking. 72" wide shelves include one center support, 96"W shelves have 2 center supports. Units include: starter—4 angle posts, 3 shelves, center supports; add-on—2 T-posts, 3 shelves, center supports. Made in USA.NOTE: Capacities are the maximum each shelf will hold and are based on evenly distributed loads. Combine to form rows. Add-ons include a pair of T-posts. Begin rows with posts from starter and join any number of add-ons to complete the row. Finish with posts from starter unit.