Keep your plants perfectly watered! Water from a stone slowly lets water out into your planter over the course of 3-4 days. A useful addition to any gardener's home. Made from hand-blown glass. Holds 7oz (207ml) of water. Instructions are: 1. Remove the cork and fill the stone with clean water and replace the cork. 2. Turn over and test to make sure water is coming out of the water release hole. 3. Place the stone in your planter with the cork facing down. 4. Make sure the stone is placed on a level surface with the water release hole not obstructed. Incorrect set-up will lead the water flowing out too fast or not at all. 5. Once the stone is in place tap it a few times to make sure water is flowing, the bubbles rising from the water release means water is following properly.