Built with True Wireless Bluetooth - instantly synchronize with each other yet work independently. IPX5 Rated rain and sweatproof to fit your active lifestyle. APTX Lossless Audio - reproduce pure sound as artist intended. Music and call control - answer a call change tracks play/pause and more. Ambient Noise Suppression - unwanted noise is reduced so you can focus on the music. Echo canceling and noise suppression ensures voice is heard clearly. Rapid 15 minute charge provides 1 hour of playback. 12mm Driver size. Frequency range: 20Hz-20kHz.