Power supply: DC 3V-5V Audio output amplitude: 950MV ± 50MV 47KΩ EN Foot: The Bluetooth connection, output high (+3.3 V Back to even function: automatic back even Automatic control technology: 1. search, matching, automatic ------- connection on the phone or computer can operate 2. signal input automatic switch ------- wired input seamlessly with Bluetooth input When the Bluetooth connection is