33 pcs Long 5/16" Lag Bolt Shields 5/16 x 1-3/4 Concrete Anchors 1/2" Drill
Drill a 1/2" O.D. hole about 2" deep in a concrete or masonry surface and insert this sleeve. Then, you can thread a standard 5/16" x 2" lag screw into the sleeve for a secure friction grip in the concrete.