Fast installation - self drilling unusually high holding power for 3/8 inch to 1 inch wallboard the fastest & easiest hollow wall anchor you can use in wallboard the unique drill tip configuration uses four offset blades to insure fast and true cutting two blades are cutting blades, the other two stabilize the anchor for speed and accuracy a unique thread design with thin, knife-like oversize threads achieves unusually high holding power in gypsum without sacrificing speed the tapered root compacts the wall material around the anchor, increasing the holding power anti-rotation ratchet teeth under the collar secure the anchor when removing the screw made of tough du pont zytelnylon or zamak the zytel zip-it is tough and electrically non-conductive, while the zamak zip-it is metal and very strong.