Use these Blue Wave Cover Clips to ensure your pool cover stays in place. Each one of them can be put in a specific place around the unit so the cover is evenly held down. The fastener clips grip your top rail like a clothespin and hold your cover tightly in place. It s recommended that you use two clips per upright. The durable PVC construction allows them to handle outdoor conditions while remaining in place. They re designed to be simple to install as well as remove when needed. The clips will make a useful addition to your pool accessories.