1、Built in Music: Built in 20 white noise and 4 sleep music, stereo sound. White magnetic horn, shock bass. The position of the headset can be adjusted to suit different people's head circumference 2、Large Capacity Battery: The sleep eye cover has a full capacity battery of 300mAh, which guarantees 10 hours of continuous music playing 3、Fast Transmission Rate: Using Bluetooth V5.2 chip, the transmission rate is fast and stable, the transmission distance is more than 20 meters 4、Voice Prompt: The sleep eye cover has English voice prompts for power on, power off, successful pairing, and maximum volume. For iOS system can display battery power and activate the Voice Application Intelligent assistant 5、Excellent Light Blocking Effect: Sleep eye cover adopts personality design, excellent light blocking effect. You can also put hot compress pack, cold ice pack in it Item Type: Bluetooth Sleep Eye Cover Material: Polyester Fiber Weight: Approx. 116g / 4.1oz Usage: Headwear Battery Capacity: 300mAh Battery Type: Polymer Li Battery (Shipped with Built in Battery) Charging Mode: USB Powered Charging Time: About 2-3 Hours Running Time: 10 Hours Bluetooth Specifications: V5.2+EDR/HSP/A2DP/AVRCP/HFP Frequency Range: 2.402GHZ to 2.480GHZ Transmission Distance: 20m / 65.6ft Sound Channel: Stereo Horn Parameters: 32Ω 30mm / 1.2in Horn Power: 10 Milliwatt X2 Signal to Noise Ratio: 105DB Functions: Previous Song, Next Song, Volume Up, Volume Down, Play, Pause, Answer a Call, Make a Call, Activate Voice APP, Microphone Talk 1 X Bluetooth Sleep Eye Cover 1 X USB Charging Cable 1 X Manual