A drop in water temperature is indicated by a change in the color of the leaf veins.

• ◯The best-selling betta fish product, "Betta's Sleeping Leaf," has been updated with new features, making it even easier to use.
• ◯This 4-leaf design fits perfectly even in slightly larger aquariums, and can also be separated into two sections for use in smaller aquariums. (Includes 2 suction cups)
• ◯When the water temperature drops below 20℃, the stem will turn red to notify you.