business card mp3 1) credit card sharp 2) MP3, WMA 3)128M-16G, more than 6 hours 4)MOQ: 100pcs business card mp3 : specification:Memory Capacity 128M/-16GBAudio Format MP3 WMAControl Type ButtonData Transfer USB 2.0Compatible Operating Systems Microsoft Windows 98/SE/2000/ME/XP/Vista/7, Mac OS 8.6, Linux 2.4.2Battery Type Built-in Rechargeable Lithium-Ion BatteryWork Time 3-5 hoursDimension ...