ALLMET Behind-the-Neck Bluetooth Headphones, USB Sports Stereo Wireless Bluetooth Headset Headphone for Apple iPhone X / 8/8 Plus, iPad, Blackberry, HTC, Samsung, Cell Phone and Laptop PC (Blue) Unique around-the-neck design that's lightweight and comfortable for all-day use Typical Standby Time: 160 hours 4-times anti-noise technology ensuring excellent sound quality, safety & low radiation Built-in Rechargeable Li-Polymer Battery Range of Frequency: 2.4GHz-2.4835GHz ISM Band