Tremor is an extremely rugged, high performance 50W RMS ( 400 watt peak Bluetooth speaker sound system, professionally tuned and crafted for the audiophile. You can rock out with Tremor from sunrise to sundown with its rechargeable 20,800mAh lithium polymer battery. Theres no other Bluetooth speaker that can play louder and longer, with its combination of advanced technologies and audiophile sound tuning that reproduce the fullness, clarity and depth of your music the way the artist intended. Its equipped with Bluetooth 4.0 and NFC for easy pairing with your mobile music devices. If one Tremor is simply not enough sound to rock the party.