Ximico Lm317 in Dc or Ac Converter 4v-30v Out Dc 1.5v-27v 1a input: DC or AC 4V-30V Output: DC 1.5V-27V 1A This subwoofer amplifier is used fiber glass PCB All Ximico products are backed up with LIFETIME WARRANTEE - For any reason you are unsatisfied with our product at any time, simply contact support for exchange or refund