MagniMoist inserts are placed in the bottom of flower pots. MagniMoist doesn’t let water escape from your basket until your plant is completely hydrated. When you water, MagniMoist’s smart natural fibers deflects water back into the dry soil above it. Then when the soil is fully saturated, the fiber becomes porous and releases only the excess water. Proven to outperform old fashioned coco liners. 12.5″ inserts fits pot with 12.5″ bottom.