Sharkie anchors assist with safely holding things in place. This anchor features anti-rotation fins and a unique head to prevent sinking and spinning. Sharkie works in almost any building material. These can be used in both hollow & solid wall applications. Parts are engineered using durable nylon material. These anchors measure 1/4 in. wide at the head and can accomodate screw diameters from #4 to #10. Anchors are approximately 1-1/2 in. long. Includes six 6 anchors and six 6 zinc-plated mounting screws for a total of twelve 12 pieces.Ensure hole depth is at least two times 2x the length of the anchorWorks in solid & hollow wallsIn solid walls, anchor expands within hole, gripping the entire screw lengthIn hollow walls, the anchor jaws open behind material locking anchor in placeCan be used indoors or outdoorsUse stainless or brass screws in wet / exterior climatesInstalls in a smaller hole compared to leading toggle bolts