Description: Application: This under pillow speaker can accompany you to sleep, and it will turn off after 30 minutes, so you can focus on your sleep. 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 won't make you feel uncomfortable while sleeping. Advance technology: Adopts bone conduction technology, this wireless stereo speaker will provide a clear sound to you, and it won't easily disturb other people. Easy to use: With a bluetooth-compatible 5.0 function, you can connect this under pillow speaker to a phone and start to play your soothing music to help you sleep. Specification: Bluetooth-compatible version: 5.0. Connection range: Approx. 10m/32.81ft. Material: Plastic. Working voltage: 3.7-4.2V. Vocalism unit: Bone conduction. Frequency response range: 40Hz-20KHz. S/R rate: 75dB. Battery: Polymer battery, 400mAh(Built-in). Music play time: About 20 hours. Standby time: About 300 hours. Charging voltage: 5V, 400mA. Charging time: About 2 hours. Size(LxWxH): Approx. 15.5x3.6x1.2cm/6.10x1.41x0.47 inch. Channel: 2. Audio crossover: Full-range. Input power: 25W. Rated power: 4W. Impedance: 2. Sensitivity: 32dB. Total Harmonic Distortion: 1%. Note: There might be a bit of color distortions due to different computer resolutions. There might be a slight error due to different hand measurements. Package Includes: 1 Piece Speaker(with 1 Piece Charging Cable, 1 Piece User Manual).