round 4" (short) subwoofer, 220V, with USB & SD, blanket or artificial leather surface, different colors are availale round 4" (short) subwoofer,220V,with USD & SD,with or without plastic covers on both ends,blanket or artificial leather surface,suitable for home or public places. 220V round (short) 4" subwoofer /active subwoofer/powered subwoofer (RS-4K220)