woofer and two 3 in.4-volt, 4,400 mAh Li-Ion Battery, so it can be used as a power bank.1-Channel 90-Watt-RMS Rechargeable Portable Bluetooth Party Speaker and PA System tweeters. It's also WaveSync enabled so if you buy 2 of these, they can be paired to double the volume when audio is being streamed via Bluetooth.