Item Type: White Noise Machine Material: Plastic Product Size:Approx. 10 x 9.9 x 5.4cm / 3.9 x 3.9 x 2.1in Type of Battery: Lithium Battery 3.7V2000mah (shipped with Built in Battery) Usage Time: 5 Hours Charging Time: 2 Hours Package List 1 x White Noise Machine 1 x USB Cable 1 x User Manual Shipment with built in battery. 1Better Sleep: White noise machine has a calm and natural sound, which makes babies sleep more calmly, and enables them to sleep better and have more sleep time. 2Save Space: White noise sleep device is a portable design, which takes up a small space on the bedside table and can be easily put into a bag or suitcase. It is a perfect travel companion. 3Rich Sounds: Portable white noise machine has built in 8 major music tunes and 10 natural white sounds, which can help relieve anxiety and stress and make you fall asleep faster. 4Warm Light: Smart sleep instrument has 8 lighting colors and free automatic circulation mode, which creates a better environment for sleeping, and is also convenient for getting up and feeding at night. 5Multifunctional: Mini white noise machine is not only a sleep aid, but also produces sound that can help block and cover up external noise, so it is very practical.