an anchor for securing a net cord to a base layer such as carpeting or a thin layer of plastic has a spiral - shaped flange at the end of the anchor which is disposed adjacent the rear surface of the base layer when the anchor is installed . the spiral flange allows the anchor to be mounted to the base layer with a simple twisting motion and without requiring access to the rear surface of the base layer . the anchor is able to swivel freely about its axis yet is highly resistant to being pulled out of the hole . an installation tool has prongs for engaging detent bumps on the anchor and is used by a worker to hold the anchor while it is being mounted the base layer .