PoolTux CSPTBSL20401 20' x 40' Blue King Solid Rectangle Safety Cover with Center Step. King Swimming Pool Safety Covers add a touch of class to your swimming pool over the winter with a PoolTux King solid swimming pool safety cover. These versatile solid swimming pool safety covers offer a unique combination of performance, ease of maintenance and superior protection. The two-ply bias weave solid material keeps debris out, yet allows rainwater and melted snow to drain through. King pool safety covers are lightweight and easy to install and remove. We are so confident in our King solid swimming pool safety covers, that we stand behind them with a warranty the other only give to high end covers.