Popular hamburger mini TF card speaker, high-fidelity, low-power; for MP3, ... ;aluminum shape;last for 4 hours Product Features:1. TF card readability / Certificates: CE, ROHS, One year warranty / ... next, volume++/--, power on/off.7. 3.5 mm audio retractable cable can connect with PC, Mobile, Mp3, Mp4, ... (Big cube packing) Popular hamburger mini TF card speaker for mobile,laptop,iphone, with bluetooth