Quad Balanced Armature (BA) driver system. Driver Type: Balanced Armature (4 drivers). Type: In-Ear Earphones (Wired). Sony XBA-4SL In-Ear Earphones. Wired in-ear design for stable, lossless audio. This is an authentic Sony XBA-4SL in-ear earphone, a high-end wired model designed for audiophile-grade sound quality.
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