Compatible with Sennheiser PXC 550-II Wireless, PXC 550 Wireless case. - Compatible with Sennheiser HD 350BT, HD 300, HD 458BT, HD 450SE, HD 100 case. - Compatible with Sennheiser HD 4.50BTNC, HD 4.50 SE, HD 4.50, HD 4.40BT, HD 4.40, HD 4.30i, HD 4.30G case.
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