Without a power cord, Genius presents a portable speaker you can use anywhere, the SP-i170. Whether you are indoors or outdoors, you can always enjoy your favorite music anywhere for up to eight hours of battery built. SP-i170 uses a bass driver 1.5 "metal to make the sound deeper and broader. Charging is simple, just plug it into the USB port of a PC or laptop. Adapter is not necessary and can be used with any laptop, mobile phone, iPhone / iPod, MP3/MP4 player and CD player that has a standard audio input 3.5 mm. For other applications, SP-i170 speaker has a convenient volume knob where you can adjust the volume as desired. Four colors: polished black, white, pink and blue. Features include a quick charge USB cable and a carrying case for storage.