Kt900Dsp Feedback Suppressor Preamp Preamplifier Karaoke Effector Digital Product Features Digital Pre-stage Effector Anti-howling Audio Processor Echo USB MP3 Bluetooth Optical Built-in effect chip, Bluetooth connection to enjoy music.KTV pre-stage reverberation effector. Support 4- way input, audio input, AUX audio input, Optical fiber with antenna, USB and Bluetooth . You can press the INPUT key to switch the input of each audio source. Support subwoofer output, Center Speaker Output, recording signal output and XLR output port.Note: If optical fiber connection is used, the buyer's audio output device must have optical fiber output interface to use 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. weddings, concerts, bars, outdoor performances and other occasions. Shipping: Shipping is complimentary within the lower 48 US States. We Do Not Ship to PO/APO Boxes, HI or Alaska We Do Not Ship Outside of the Continental US All items ship within 24-72 hours of Payment For large items that require Freight shipping a valid phone number is required to call and schedule your delivery Terms of Sale and Feedback: Feedback is extremely important to us and If you are satisfied with our transaction, please take a moment to leave Positive Feedback. YOUR Satisfaction is our #1 Priority! If there are any issues, PLEASE contact us BEFORE leaving a neutral or negative rating so that we may resolve any concerns. We PROMISE we can make you happy if you give us a fair chance. Returns / Concerns: All items qualify for returns within 14 - 30 days of receipt. Buyer is responsible for return shipping on any item that is not damaged Please be sure this is an item you want before making your purchase. Customer Satisfaction is our TOP priority! All items are IN STOCK at time of listing. Inventory changes constantly and it is impossible to maintain a perfectly accurate count of all items. Please do not penalize us if we have to issue you a refund! Thank You For Your Business!