What are the specifications regarding the audio performance of these earbuds?

These earbuds have an impedance of 32 Ohm and a frequency response range of 20 Hz to 20 kHz.

What type of connection do the Maxell Fusion X Earbuds use?

The Maxell Fusion X Earbuds use a USB Type C connection.

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Maxell Fusion X USB-C Earbuds - Stereo - USB Type C - Wired - 32 Ohm - 20 Hz to 20 kHz - Earbud - Binaural - In-ear - 3.94 ft Cable - Black