5/16", ALLIGATOR® Anchors, Drill Flush Mount, Polypropylene, A8

ALLIGATOR anchors are designed to hold high loads in solid walls, ceilings, and floors - but also hold securely when they encounter an unexpected cavity, such as in hollow brick or hollow block, or even in drywall or, especially, in tile over drywall. The specially formulated polypropylene body flows into and locks up with any undercuts in the hole, bonding the screw to the wall and sealing the hole to prevent moisture from entering.