A cable and winch (not included) is the most reliable method for securing a pool cover on an above ground pool. To install, feed the plastic-coated cable through the grommets around the outside-edge of your winter pool-cover. Then use a winch to tighten the cable. The 120' cable will fit above ground round pools up to 33' and oval pools up to 21' x 41'. Turnbuckle sold separately.