Balcony Plant Watering System \"Hydro Classic\" - Turns PET bottles into abundant water reservoirs Always the right amount of water for your plants. Our window boxes irrigation system \"Hydro Classic\" supplies your plant roots with the optimal amount of water, so you can, for example, enjoy your weekend getaway. Simply place watering heads on the bottleneck of a PET bottle filled with water, insert clay cones into the soil to be watered and relax while \"Hydro Classic\" takes care of everything else. This balcony plant watering system is suitable for PET bottles up to 1.5 litres. The practical special adapter ensures a guaranteed, drip-free change of bottles. \"Hydro Classic\" comes in a practical set of either two or four. Also suitable for indoor plants and especially for larger potted plants. This way your horticultural treasures never go thirsty again!