Item Type: Bluetooth Pillow SpeakerMaterial: ABSBluetooth: 5.1Transmission Distance: Approx. 5m/16.4ftFrequency Range: 20-20KHzMemory Card Support: Up to 128GB (Not Included)Battery Type: Built in 400mAh Lithium Ion BatteryPackage List1 x Bluetooth Pillow Speaker1 x Instruction Manual1 x Data Cable1Advanced Technology: The pillow speaker uses the latest conduction technology to deliver sound to your ears in a vibrating, compact and portable way through your pillow. 2Soft Whisper: The bluetooth pillow speaker produces a soft whisper that helps relieve stress and helps you fall asleep faster. 3Improve Insomnia: Mini portable under pillow speakers provide great help for adults and babies to fall asleep and get rid of insomnia. 4Supports Memory Card: The pillow speaker can be inserted into a maximum of 128GB Memory Card to use to store songs. (Note: Memory Card is not included in this product) 5Compact and Mini: Portable under pillow speakers with mini size and low volume design, most suitable for side pillows.