The Monster Air Free Bone Conduction Headphone is perfect for those who want to enjoy high-quality music while on the go. With a wireless Bluetooth 5.3 technology, you can easily connect to any device and enjoy your favorite music without any hassle. The ear-hook design provides a comfortable fit, making it suitable for work, commute, travel, or play.The headphones come in a variety of colors, including gray, purple, and black, and have a frequency range of 20Hz-20kHz and an impedance of 32 ohms. The built-in microphone allows you to take calls hands-free, and the bone conduction feature ensures that you can hear your surroundings while still enjoying your music. The Monster Air Free is a unit that is perfect for anyone looking for a high-quality pair of headphones that are both stylish and functional.