SUStee is a ‘watering checker’ that can tell you when to water your plant by changing its colour. Just stick this fail-proof device in your plant pot, and you’ll be at ease for quenching your plants’ thirst. One SUStee per pot takes away all your troubles. No batteries needed. SUStee is the perfect solution for all plant lovers who don’t know how often to water their plants. Simple to use: leave the device in the pot to continuously monitor soil humidity and show you when to water your plants. SUStee will turn from blue to white when your plant needs to be watered. Suitable for all kinds of plants and all kinds of soils. SUStee’s inner core can be manually replaced. Depending on the type of soil used, the inner core has a life span of 6 to 24 months. SUStee 36pcs pack is a table display with 36pcs of SUStee. Each Sustee is equipped with a removable barcode sticker. SUStee Large is used for pot diameters > 18cm.