A pack of 4 insert replacement sticks for medium-sized sustee watering sticks - Replace core every 6-9 months for best results Easy-to-replace core refills – Simply twist off the cap, remove the used core, insert the new refill, and replace the cap. The core turns blue when the plant has enough water and fades to white when it needs watering Sustee collaborated with Tokyo University of Agriculture to improve the design and function of each stick Materials: polycarbonate (main body), nonwoven fabric treated with preservatives (refill) Individual refill insert dimensions: 0.4 x 0.3 x 7.1 inches (medium) - Made in Japan, Weight: 0.00771617917 pounds, Manufacturer: キャビノチェ