Bests & Worsts Reviews from Amazon

If you don't like the wind noises while running or biking, and want to be vigilant of your surroundings, then this is THE ONLY headphone in the market that suits your need. I used to go with Sennheiser PMX 680 for many years and finally found an alternative to that. If you like PMX 680's ergonomics, and don't like using in-ear while running, then again this is for you. If you don't want to hear the surroundings and want to have a closed-back headphone experience, like in the gym, please just use the ear plug offered for free in the box. I guarantee you that the "reduction in dB of the external sound" is light years better than overpriced garbage like Bose QC (which has terrible isolation in mid-low frequency range), because the ear plug literally forbids you hear anything except the vibration conducted by your bones. Seriously, to those who said sound quality, this is a bluetooth headphone with 10 ohm impedance with design aiming to get through a 4 hour marathon. Being an audiophile myself owning multiple high-end headphones, I find the sound quality of this headphone is more than acceptable during working out. If you like sound quality why don't you bring your Tesla T1+amplifier in a run. Indeed the bass is lacking, however, the reason you feel the bass is lacking is because you listen to garbage (like Beats with high distortion and atrocious frequency response) too much. The tone of this headphone is more like a reference headphone (Sennheiser HD280), yet with less resolution.