It has a slim, minimalist aesthetic that doesn't take away from the beauty of the plants, harmoniously blending in when left in the soil. It works with almost any plant that grows in the soil. When using the moisture testing stick, the white color indicates that the watering, and the blue color indicates that it has enough water. The core insert that determines if watering is needed can also be manually replaced. Extend the life of your beloved houseplants with the Aquameter soil moisture meter for indoor and outdoor plants. is designed and Japan and is the perfect addition to various houseplants. Senses water at root level, no dirty fingers & damaged trying to gauge soil moisture. Moisture meter for house plants. Award-winning product design, environmentally friendly, and maintenance-free (no battery required) - Creates little waste Dimensions: 7.09 x 0.39 x 0.31 inches (medium) - Intended for pot sizes of 3.5, 4, 5, and 6 This leave in soil moisture meter is maintenance-free. A perfect plant watering indicator for potted plants. It is recommended to replace the refillable core of your after 6- of use. has multiple international awards including the Reddot Design Award, Germany Design for Asia Award, and the Japan Good Designs Award. The medium size is meant for pot sizes 3.5, 4, 5, and 6. Two sticks are included., Manufacturer: CTRLZS