FREQUENCY SETTINGS Powered by a rechargeable lithium-ion battery, the Walker's Razor XV 3.0 features hi-gain, omnidirectional microphones for crystal clear ambient sounds with 4 independent frequency settings to fit your specific needs. COMFORTABLE FIT 3 pairs of foam tips in different sizes offer a sure, comfortable fit, while independent volume controls allow you to adjust the volume in each ear. RECHARGEABLE BATTERIES This Walker's headset features a rechargeable lithium battery; there's no need to remove the batteries to recharge them with the integrated USB charging port with an included USB charging cable. BLUETOOTH The Razor XV 3.0 headset is a Bluetooth device that is controlled by the free Walkers LINK app that allows for complete control of your device from your smartphone. Retractable digital earbuds with a noise reduction rating of 31 dB. Hi-gain omnidirectional microphones for clear sound enhancement HD Walker's earbuds for a wide range of audio quality 4 frequency modes: Universal, Speech Clarity, Hi-Frequency, and Power Boost Independent volume control for perfect listening Earbuds in an improved position for less cord interference 3 pairs of foam tips (S / M / L) included Integrated micro USB port Rechargeable lithium battery Micro USB charging cable included