Hydrospike High Performer BlueTip Series, Worry-free Automatic Watering Kit, 3-pack, HS-350 "BlueTip" series is top performer in its class. Automatically maintains optimal soil moisture level via capillary action Simple and easy to use -- uses no electricity, and has no complicated settings Can be used to water small or large houseplants, just use two or more spikes to increase watering capacity. May be used in conjunction with liquid fertilizers to improve soil nutrient levels. Each pack contains 3 ceramic spikes; all that's needed is a separate container for water placed near the plant.