Maximize your relaxation with the comfort of this form-fitting sleep mask that doubles as Bluetooth headphones. The two speakers fit right over your ears so you can listen to your favorite music or podcast via Bluetooth as you hunker down for some well-deserved rest. For particularly sleepless nights, listen to one of the preprogrammed white noise selections to drift off peacefully. Number of Batteries: 1 Included: 1 Instruction Manual(s), 1 Usb Cable(s), 1 Carrying Case(s) Features: Rechargeable, Adjustable Headband, Blackout, Bluetooth Compatible, Built-In Microphone Battery Type: Lithium Ion Impedance: 32 Ohms Manufacturer Warranty: 90 Day Parts Limited Power Source: Battery (included) Measurements: 17.13 Length/Inches, 4.13 Height/Inches, .98 Width/Inches Minimum Frequency Response: 20 Hertz Maximum Frequency Response: 20 Kilohertz Weight (lb.): 0.2 Lb Country of Origin: Imported