Quickly and securely set expansive screw anchors in masonry, regardless of thickness | Screw Anchor Expander | Expansive bolt size 1/4-Inch -20 | For use with caulking anchorsAmazon.ca Product DescriptionGreenlee's screw anchor expander quickly and securely set expansive screw anchors in masonry, regardless of thickness. Made from hardened alloy steel.From the ManufacturerGreenlee's screw anchor expander quickly and securely set expansive screw anchors in masonry, regardless of thickness. Made from hardened alloy steel.