Color: gray. Power: 7.5W. Working voltage: 3.7V. Charging voltage: 5V. Charging current: 2A. Battery type: 18650 lithium battery. Charging time: about 4 hours. Usage time: 90 minutes. Features: Air pressure massage imitates real-life massage techniques with four levels of massage intensity to quickly relax muscles and relieve leg pain and discomfort. Large-area constant-temperature hot compress with three adjustable temperatures and 360-degree wrap to eliminate leg fatigue. Effectively promotes blood circulation, improves cold legs, sore legs, leg pain, muscular legs, and creates beautiful legs. Four levels of intelligent timing, with a default 15-minute work countdown when turned on, making it more convenient for you to use. Type-C charging, 15 minutes of use per day, up to 6 days of use, giving you a comfortable and relaxing massage experience anytime, anywhere.