Please contract us firstly if there are any problems when you received the package. Notes: Not for trucks. Max Output Power: 1200W. High level Input Sensitivity: 0.9v. Low Level Input Sensitivity: 300mV. Low Pass Filter: 50-150Hz. Fully functional and easy to debug. Slim fuselage, installed under the seat. Design of high temperature resistant coil. Fine workmanship and good performance. 6″8″ speaker gives A different kind of heavy bass effect. If you would like to. Please feel free to write to us. We have a large number of high quality stocks available for sale in bulk, and we can offer. Based on the quantity ordered. Message for address and reference number before return. If there are any questions about us (orders or product or services or suggestions). Good communication is helpful for both of us to resolve any problems and issues.