Damgoo Zk-502T Bluetooth Amplifier Board With Treble And Bass Control, Tpa3116D2 Product Features TPA3116D2 HIFI Chip Solution: Stereo Dual-channel Output to Ensure Continuous Serial High-power Operation, THD ?0.1%. Wide Voltage Input DC: 9-24V; Treble Bass Control: If You Are Tired of The Inherent High Low Bass, Why Not Try The High Low Control Knob! This Will Make You Feel Like Being In A Movie Theater.? BT and AUX Function: BT5.0 version, Transmission Distance Is Farther. The Transmission Distance Can Reach 49 Feet In An Open Environment. If your Play Device Does Not Have BT, You Can Also Input Audio Signals Through The 3.5MM Headphone Plug.? Safety Protection: This Amp Board Has Overheat Protection, Circuit Protection, Over-voltage and Under-voltage Protection? 7 * 24 Hours After-sales Service: Paying Attention To Customer Experience And Satisfying Customers Is Our Service Tenet. If You Have Any Questions About The Product, or The Product Has Quality Problems, Please Contact Us At Any Time, We Will Give You A 100% Satisfactory Answer. 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!