round 4" (long) subwoofer, home audio, power subwoofer 220v, USB & SD surface:artificial leather color:black round 4" (long) subwoofer, home audio, power subwoofer220v,with USB & SD,blanket or artificial leather surface,different colors are available,with plastic covers on both ends,suitable for home or public places. 220v round 4" (long) subwoofer,home audio, power subwoofer (RL-4K220)