Sennheiser HDB 630 Wireless Audiophile Headphones - High-Res Sound with Parametric EQ and Crossfeed, Bluetooth Headset with ANC and 60h Battery Life, Lightweight Design, Clear Calls - includes BTD 700. Flawless sound, no wires, and a battery that lasts for up to 60 hours. The Sennheiser HDB 630 lets outaketrueaudiophilesoundanywhere you go. Precision engineering brings out breathtaking clarity, a neutral tone, detailed mids, and a wide soundstage. Use aptX HD and aptX Adaptive Bluetooth® codecs from a high-resolution source such as Sennheiser’s BTD 700 Bluetooth® adapter or plug in via USBC for pure fidelity. The advanced parametric EQ lets you define frequency bands and filters as you please. Cross Fade balances classic tracks for better headphone listening while Active Noise Cancellation eliminates background noise while maintaining high-end audio quality.