The Depusheng Rev3900 Pre Effector Is A Professional Ktv Household Karaoke Product Details Built-in microphone receiver, no need to connect wires, simple operation, line-of-sight receiving 30 meters KTV pre-stage reverberation effector: New upgrade, built-in effect chip, Bluetooth connection to enjoy music. Multifunctional input port: front panel 2-way/rear panel 2-way microphone input interface, which supports microphone volume adjustment/bass adjustment/treble adjustment; Optical fiber/Bluetooth/USB audio input is supported. Intelligent one-button howling prevention: Using multi-point frequency shift technology can effectively suppress howling, and at the same time avoid voice collapse, so that your singing is incisive and vivid. Various music parameters fine-tuning: Using hidden metal adjustment knob, you can adjust music and vocals in detail, and you only need a single screw to adjust, so you can easily obtain professional singing level. Widely used: weddings, concerts, bars, outdoor performances and other occasions.?If there's any problem, please don't hesitate to contact us, we are very happy to help and strive for good customer service.? Payment We accept PayPal and credit cards via PayPal. Taxes - US We collect sales tax, as required by law. Shipping We make every effort of shipping within 3 business day of payment clearing. The estimated delivery time is 2 - 5 business days from the shipping date. Policies If you do need to return your item, please contact us via email (you will receive an email when your product ships with additional details - Subject: Important information about your purchase). You will then be provided with a return shipping label and packing slip. Pack the item carefully. Include the packing slip, apply the shipping label, and return the item within 30 business days of the date you request a return, or your return will be canceled. Once we receive your order we will inspect the return. Please allow up to 5 business days of receiving the returned item for your refund.