Specification: Product Name: Car Amplifier. Subwoofer Type: Subwoofer Speaker. Color: Black. Material: Metal. Channels: 1-Channel. Operating Voltage: 12V. Frequency Response: 30Hz~280KHz. Rated Power: 600W. Peak Power: 1000W. Impedance: 4-8 Ω. SNR: 105dBA. THD: <0.1%. Size: 23.5x15.5cm (LXW). Qty: 1pc. Features: -Current Overload, Short Circuits, Thermal Overload, DC Offset. -Mono 1000 Watts Car Audio Amplifier gives you a wonderful in-car entertainment. -High power, good sound quality, no distortion, give you a great hearing enjoyment. -Light weight, handy and easy to install. -Powerful bass. Wiring: 1. Speaker connection: amplifier board has a good piece of red and black wire welding can be accessed by a 4-8 Euro 100-150W bass or     full-range speaker or speakers (red pick horn + , black pick speaker - is recommended to use 4 ohm     8-12 inch 45 core 100-170 magnetic bass ); 2. Power connection:     A. Car has a CD player: GND then negative vehicle power ; 12V 12V power supply connected to the car s positive;         REM CD player connected to the control line (sothe CD player can directly control the subwoofer amplifier on and off )     B. Car no CD player: GND connected to the negative power of the car , + 12V and REM connected together in positive 12V         car power ( + 12V can also be an indirect one with REM switch control amplifier switching function );     C. Directly with the battery (battery) connection: GND connect the battery negative , + 12V and 12V REM then the positive         attery simultaneously. Note: 1.We provide clear pictures, measurements where possible. Please check as much as possible to make sure the item is the one that you need. 2.Please allow 0.5-1 inch difference due to manual measurement. (1inch=2.54cm) 3.There are no instructions included in this kit.Professional Installation Is Highly Recommended Package Included: 1 x Car Audio Amplifier Board