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. Speaker give different kind of heavy bass effect. Communication is always the best way to solve problems. We accept any return within 30 days of our promise. Please do not return the package without consent. It is impossible for us to get the package. As you know, feedback is important to all sellers. We strive to provide 5-star service to all customers. Because it helps us maintain quality service. Communication is very important, and we believe that we can solve all problems for you.