The QOLTEC 50816 is a pair of Bluetooth headphones with a microphone, USB, and USB micro connectivity, and a black design. The headphones have a built-in microphone, allowing users to take calls hands-free. The headphones also offer excellent sound and noise cancellation, making it ideal for listening to music, gaming, and more. The headphones come with an adjustable headband for comfort, and a 3.5mm jack for connection to other audio sources. The headphones are powered by a rechargeable lithium-ion battery and can provide up to 12 hours of playing time. Additionally, the headphones have an integrated hands-free calling system, built-in volume control, and voice command functions.