LAB POINTS - Teenage Engineering x AIAIAI collab - same design-ethos as the OP-1 synth - full frequency response with emphasis on low and mid range - includes 3 sleeves for comfortable fit - compatible with iPhone, iPad, iPod MANUFACTURER'S REVIEW Jesper Kouthoofd from Teenage Engineering has designed the PX-0 and the aesthetics of the earphone follows the same design-ethos as the OP-1 synthesizer. The sound has been tunes by AIAIAI and the result is a well-defined frequency response and full spectrum sound with an emphasis on low and mid range, but still with distinct clarity in the high-range frequencies. The PX-0 comes with three different sleeves for better custom fit. The PX-0 is compatible with iPhone, iPad, and iPod.