Concerning this item PRO HI-RES CERTIFIED LEGENDARY SOUND: With any frequency or volume, JBL's Tour One M2 40mm drivers produce clear, accurate sound with reduced distortion. Your music will always sound its best thanks to their support for frequencies up to 40 kHz and Hi-Res audio certification. TRUE ADAPTIVE NOISE CANCELLING: This technology reduces distractions when you need to concentrate by using microphones to adjust background noise 50,000 times per second. A maximum of fifty hours of playtime: When noise cancellation is turned off, the JBL Tour One M2 can play music for up to 50 hours; when it is turned on, it can play for 30 hours. Up to five hours of playback is possible with just ten minutes of charging. Additionally, a 4-MIC Aux Cable for wired listening is included.