Listen, loop, and rewind audio on-the-go with the matte black Teenage Engineering OB-4 Magic Radio, Recorder, and Speaker with Bluetooth. Source your audio by streaming via Bluetooth from a mobile device, use the smart antenna to dial in FM radio, plug in an audio device via the 3.5mm line in jack, or access the experimental disk mode. Whatever you play is continuously recorded on a rolling 2-hour loop tape, so you can rewind and listen again. Whey playing audio, clear and dynamic sound emit from the OB-4's two built-in woofers and tweeters powered by two 38W Class-D amplifiers.