Retain-Its are tough high density polyethylene disc that fit into form holes to offer snug support of dowels. It snaps easily into 2 1/2′ diameter form holes as blanks or in support of bars. No tools are required for setting. The interior profile is only 1/16′. Disc sizes are blank and bar sizes 8, 10, 12 , and 16. They are sold in boxes of 250 pcs.