OCM Slab Bolster Upper - Plain metal bar supports are used in commercial concrete projects to support reinforcing steel in elevated concrete decks, footings, slab on metal deck, bridge decks and other applications. Available in heights ranging from 3/4" to 6" in 1/4" increments. Other sizes available by request. Manufactured in 60" Lengths. Manufactured from wire conforming to ASTM A82/82M.