[Easy to Use] No battery or electricity needed, this water level gauge is simple and convenient to use, just plug and use. [Convenient Observation] This water level indicator can show the water level to remind you to water. If there is no water in the flower pot, the water level gauge float will drop to the bottom. When you add the right amount of water, the buoy floats. [Important Reminder] If there is no water in the pot, the water level gauge float is at the bottom. In that case, pull up the water level and water the plants through the hole [Wide Use] This water level gauge is used for flower pots and is a perfect tool for indoor and outdoor use. Color: White Material: plastic Size: 20 cm Package contents: 10 x water level indicator Only the above package content, other products are not included. Note: Light and different displays may cause the color of the item in the picture a little different from the real thing. The allowed measurement error is +/- 1-3 cm.