Product information: Material: Super soft Purpose: Anti-light radiation Specification: Enjoying black Bluetooth version: 5.0 plan Bluetooth call: full duplex Wireless distance: barrier-free 10 meters and above Frequency range: 2.402GHZ Talk time: 15 hours Standby time: 180 days Receiving sensitivity <-80dBm Rechargeable battery: 150 mah Charging voltage: 5V 0.7 Size Information: Package: Eye mask x1