The mini pillow speaker is designed to reduce stress and help with deep sleep, providing great help for adults and babies to fall asleep and get rid of troubles. Material: ABS Product size: 123*38*15mm Colour: black Bluetooth Version: V5.0+EDR Frequency range: 80HZ-18KHZ Charging interface: Type-C Output power: 8Ω2W Support audio format: MP3/WMA/DMV Support: TF card (maximum 32GB) Playback time: more than 8H Battery type: can work more than 8 hours, charging time is only 1 hour (built-in) Bone Conduction Technology The portable pillow speaker adopts bone conduction technology, allowing vibration to be transmitted directly to your inner ear through the pillow. Long-lasting battery Built-in 350mAh battery can work for more than 8 hours, charging time is only 1 hour. Adopts high quality chip to ensure stable and clear sound. Can be used for a long time, so that you can sleep more peacefully at night. Convenient to carry and use on the go. Small and lightweight Sleep music box small will not make you feel any foreign body feeling and uncomfortable. You can easily carry it when travelling or business trip without taking up too much space. Helps you create a comfortable sleep and get rid of.