PENDULUMIC TACH T1 Wireless Headphone Naturally Smooth Controls - The iconic PENDULUMIC Dial for instinctively natural controls over your music playback, volume and call controls Smart Wireless-Wired Mode Operation - The T1 detects and switches automatically between Wireless, Amplified and Passive wired modes, depending on your usage setting and scenario Never Stop Playing - 25 hours of wireless playback with AAA battery backup. Switch to Amplifiedwired mode for extended playtime or Passivewired mode for batteryless operation Low Latency Wireless - Enjoy music, movies and games wirelessly with no noticeable lag Dual Sharing - Share and enjoy music or audio together with a friend on another T1