PoolTux CSPTBME18400 18' x 40' Blue Royal Mesh Rectangle Safety Cover. PoolTux Royal Mesh Pool Safety Covers are of a tightly woven mesh pool safety cover material giving you affordability and pool protection with uncompromised quality. Dirt and debris are kept out, yet still allowing water rain and melted snow to easily drain through. Mesh pool safety covers make for an easy spring opening because they keep all of the big stuff out. We are so confident in our Royal mesh pool safety covers, that we stand behind them with a warranty the other only give to high end covers.