High-quality materials: Made of high-quality materials, long service life. Simple and intuitive, fast flashing. Two detection modes: manual and automatic. The soil is extremely dry and a red light flashes every 6 seconds to warn that watering is necessary immediately. Instructions: The green light flashes every two hours when the humidity is correct. The yellow light flashes every three times for two hours when the soil is dry. Widely used: Suitable for soil moisture testing of various indoor plants and flowers.