The stackable rebar chair's design allows 1-, 1.5-, and 2-inch coverage all in one product. It is designed with a 1-inch spacer allowing users to achieve any dimensional combination. The chairs are built to support more than 2000 pounds; an optional sand pad is also available for outdoor flatwork. This stack-able spacer joins the manufacturer's existing line of patented rebar spacers and ratchet-style rebar wheel chairs. Polylok Inc. 877-765-9565. .