1) Material Glass fiber  <br><br>2) Specification Dual Operating voltage: AC 12V (AC 12V-0-12V)? Maximum output power: left and right channels 18Wx2? subwoofer 36Wx1; Output Impedance: 4-8 ohms? PCB Features 3) Amplifier circuit uses 4 TDA2030A? 2 TDA2030A is responsible for the left and right channels. the other 2 TDA2030A is connected to BTL circuit for the subwoofer; Potentiometer From left to right as follows: Subwoofer volume? treble adjustment? the total volume  <br><br>4) Application TDA2030A 2.1 Circuit Amplifier Stereo Audio 2 Channel Subwoofer Amplifier Board  <br><br>5) Dimensions: 11.7 x 6.0 x3.5cm <br><br>6) Weight: 93g <div class="params_begin">Specification:</div><div class="params_group"><table border="0" class="params_group_table">  <tr>	<td class="params_group_name">			Package Weight		</td>	<td class="params_props">			<div class="params_prop ">		  <table border="0" class="params_prop_table">			<tr>					<td class="params_name">One Package Weight</td>			<td class="params_value">				0.14kgs / 0.31lb			</td>					</tr>		  </table>		</div>			<div class="params_prop ">		  <table border="0" class="params_prop_table">			<tr>					<td class="params_name">Qty per Carton</td>			<td class="params_value">				80			</td>					</tr>		  </table>		</div>			<div class="params_prop ">		  <table border="0" class="params_prop_table">			<tr>					<td class="params_name">Carton Weight</td>			<td class="params_value">				10.40kgs / 22.93lb			</td>					</tr>		  </table>		</div>			<div class="params_prop last_prop">		  <table border="0" class="params_prop_table">			<tr>					<td class="params_name">Carton Size</td>			<td class="params_value">				36cm * 35cm * 25cm / 14.17inch * 13.78inch * 9.84inch			</td>					</tr>		  </table>		</div>		</td>  </tr></table></div><div class="params_end"></div> <p>&nbsp;<img src="//lh3.googleusercontent.com/-oYp3-Nj18a0/Vzl4ATG8byI/AAAAAAAAiB0/flsa52IW_io-CXISwM-o_wO6Gth2NbbmgCCo/s829/sg%2Bback.jpg" alt="" /></p>