SkimDoctor Skimmer Socks Small Above Ground Size (5 Pack) Designed to work with SkimDoctor 2.0 Above Ground Chlorine tablets do not come in direct contact with the SkimDoctor sock improving durability Larger debris is trapped by the basket leaving the sock to only catch the finer particles that pass through the basket The new design allows you to only empty the basket if the sock is not very dirty and leave in place Easier and faster to clean the sock for reuse because it only comes in contact with fine debris and particles