Greenlee 868 Screw Anchor Expander For Caulking Anchor Size 1/4" - 20 Quickly and securely set expansive screw anchors in masonry, regardless of thickness Patented Manufacturer: Greenlee Quickly and securely set expansive screw anchors in masonry, regardless of thickness Screw Anchor Expander Expansive bolt size 1/4"-20 For use with caulking anchors