Bosmere 36" Pre-Formed Replacement Coco Liner with Soil Moist for Window Basket Soil moist mat works like a sponge and wil hold up to 32 oz of water 100% natural, made from renewable resources Pre-formed to fit 36" window basket The water is gradually released into the basket as the soil dries out The mat will re-absorb water when the basket is watered; Compostable at end of season