Built-in 2 bone conduction speakers, bone conduction speakers are also called bone conduction vibrators, which resonate and sound, and you can feel a slight vibration when holding it in your hand. Three-speed automatic timer shutdown, easy to set, no need to get up at night, sleep until dawn. Safe to use: Built-in polymer battery, this wireless loudspeaker is rechargeable and features a dual MOS battery protection circuit. Comfortable to use: With a small and thin bar appearance, this under pillow speaker 't make you feel uncomfortable while sleeping. Advance technology: Adopts bone conduction technology, this wireless stereo speaker provide a clear sound to you, and it 't easily disturb other people. Easy to use: With a bluetooth-compatible 5.4 function, you can connect this under pillow speaker to a phone and start to play your soothing music to help you sleep. Colour:Black Material:ABS Package Contents: 1 x Bone Conduction Speaker 1 x USB Charging Cable 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.