For more than two decades, the ER-4S has been the world’s most accurate high-fidelity, noise-isolating earphone. Because of this, and its 30-40 dB noise isolation,…
For more than two decades, the ER-4S has been the world’s most accurate high-fidelity, noise-isolating earphone. Because of this, and its 30-40 dB noise isolation,…