(5-piece set) is the perfect solution for all plant lovers who don't know how often to water their plants. Developed, designed, and manufactured in Japan. What size to buy: Small - pot diameter is less than 10 cm; Medium - pot diameter is between 10 cm and 18 cm; Large - pot diameter is greater than 18 cm. Detects water at the roots, no more dirty fingers and damaged roots trying to measure soil moisture with your fingers. Simple to use: leave the device in the pot and it will constantly monitor the soil moisture and indicate when the plant needs water. It will change color from blue to white as soon as the plant needs water. Suitable for all types of plants, all types of soil, and all pot sizes. The award-winning design of is simple and minimalist, so it doesn't detract from the beauty of your plants. is the only irrigation indicator based on the pF value (available water capacity). Professionals measure the pF value with expensive devices, but with , you can also go pro.