Wirelessly connect up to 2 smartphones or tablets to the speaker and take turns enjoying powerful sound. | Built in rechargeable li ion 7800mAh battery supports up to 20 hours of playtime and charges your device via USB port. | Take charge 4 to the beach or the pool without worrying about spills or even submersion in water. | Amplify your listening experience to epic levels and rock the party perfectly by wirelessly connecting more than 100 JBL connect+ enabled speakers. | *Please note* the JBL charge 4 does not include a USB wall adapter.