Audio-Technica ATH-CKR9 In-Ear Headphones (Open Box) - Discontinued American brand only the sleeve is different

only the sleeve is different

weight: 52 lbs

so as to realize the OTG function

Octa/Quad/Double/Single-Speed

Design with Beryllium film Φ50 mm speakers and they are much better than the Titanium film speakers

Audio-Technica ATH-CKR9 In-Ear Headphones (Open Box) - Discontinued American brand only the sleeve is differentATH CKR9 Featuring the worlds first dual phase push pull driver system, the ATH CKR9 in ear headphones deliver amazingly clear, high resolution audio. The unique push pull system incorporates two 13 mm drivers that face each other, but are wired out of phase, providing lower harmonic distortion and improved damping and bass frequency control. Machined aluminum housings reduce unwanted resonance for crisp mid and high range audio, while a stainless