Their answer to portability comes in the form of the Phonon 4000, a compact version of the SMB-02 built using the same 40mm driver on a travel-friendly foldable chassis that grips well. That grip allows for a strong seal when used outdoors, providing fantastic dynamics, in a package even more durable than its older brother. The fit of the Phonon 4000 is just right. It’s worth noting that the Phonon 4000 features the same heavy-duty cabling found on the SMB-02; it’s thicker than most portable headphone cables and super durable. Highly recommended.

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buy the phonon 4000 here https://phononstore.com/products/phonon-4000