With its high-precision 11.8 mm drivers, the ATH-CKR75BT Sound Reality wireless in-ear headphones give you superb efficiency and audio quality with the convenience of Bluetooth wireless technology. These aren’t just any wireless headphones. The powerful drivers reproduce audio with an extended 5 – 40,000 Hz frequency response and they feature a built-in amplifier that enhances the sound’s depth and resolution. And since the headphones are compatible with aptX and AAC codecs (in addition to the standard SBC codec) the high-resolution drivers aren’t wasted on a low-quality wireless feed. Strong yet lightweight aluminum housings complete the package, greatly reducing unwanted resonance for crisp mid- and high-range reproduction. The headphones also feature an in-line mic and controls, allowing you to answer calls, adjust volume and handle playback of music and videos on compatible smartphones and other devices. The ATH-CKR75BT’s behind-the-neck design conveniently situates the mic and controls for easy access. Also included are four sizes (XS, S, M, L) of interchangeable eartips, 30 cm (11.8") USB charging cable, secure-fit battery clip and a carrying case.