The smartphone speaker 20 in copper can be used alone or in tandem with the smartphone projector 20 ready assembled the innovative cardboard speaker is powered with 4 x aa batteries to give up to 30 hours playback plug smartphones mp3s laptops or tablets into the speaker wherever you are picnics parties even on the beach for music wherever you are features smartphone speaker 20 copper use alone or with the smartphone projector 20 ready assembled cardboard with metal grill