The Powers Fasteners Lokbolt 5/8" X 2-1/2" Hex Head As All Steel Sleeve Anchors (25/BX) (05035S) are a pre-assembled unit sleeve anchors. Use them in concrete block, brick and stone. Powers Fasteners is the leading supplier of concrete and masonry anchors in North America and has been a leader in the fastening industry since 1921. Powers is an ISO-9001 international anchoring products company with extensive expertise in the following groups: Mechanical Anchors, Adhesive, Light Duty, Roofing and Carbide Drill Bits.