Dynabolt Sleeve Anchor, 1/2" Dia., 4" L, Carbon Steel Zinc Plated, 25 PKMfr #: HN 1240 Red Head 1 2 in. x 3 in. Zinc Plated Steel Hex Head Sleeve Anchors (10 Pack) are designed for fastening into porous concrete, hollow or grout filled block, and brick. Common applications include installing machinery supports, window frames, partitions, cabinets, shelves and pipe supports. Red Head Sleeve Anchors are contractor grade and building code approved. Designed for fastening into porous concrete, hollow or grout filled block and