HiFi sound quality: Holographic acoustic, three-frequency are street, such as the scene of 3D realistic stereo sound quality, presenting you with an extraordinary listening experience, directional sound transmission does not leak sound. 10 kinds of sleep sound: White noise to help you fall asleep, reduce negative emotions, different sound scenarios to make you feel calm and sleep soundly. Upgrade Bluetooth 5.4: More stable connection, with lower power consumption and higher processing performance, clearer sound. Support TF card mode: You can listen to more music without connecting to your cell phone, and can play music files from TF card. Compact and portable: 50g lightweight design, flattened shape placed under the pillow without a sense of foreign body, senseless sleep.<br><br>Long battery life: Built-in 300mah lithium battery, fast charging, long standby time, can be played continuously for 8 hours. Product name:Bone conduction bluetooth sleep speaker Product Model: SLEEP BOX 3 Bluetooth version: 5.4 Product weight: 50g Product speaker: vibrator sound Rated input: 5V/300mA Input Connector: Type-C Battery capacity: 300mAh Playing time: 8 hours Charging time: 2 hours Bluetooth distance: 10 meters Operating voltage: 3.7/4.2V Product size: 155x36x12mm Colour:Black Material:ABS<br><br>Package Contents: 1 x Bluetooth speaker 1 x charging cable<br><br>Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.