... speaker Plastic housing rechargeable Li-ion battery Usage:1, Long press “MODE” : To turn on/off the ... .2, “VOL-/”: Shortly for previous song, and long for turn down the volume. “VOL+/” : Shortly for next song ... , and long for turn up the volume.3, “”: ... use long time, please charge within 2 or 3 months to protect battery to be shut down automatically. ...