Unit dimensions (Inches): 10.67" L x 5.32" W x 3.54" H. Includes Clear Lucite Unbreakable Mounting Brackets, hardware and charging resistor with instructions Today's car audio amplifiers need huge amounts of current. Often a vehicle's electrical system is unable to provide it. With your car's air conditioning running, the factory electrical charging system may already be operating at only 70% of full capacity. When a bass note hits or when playing your system very loudly, there may not be enough electrical energy to power your amplification system properly causing your music to sound strained and distorted. Rockville capacitors are designed to store enough electrical current and to release this energy extremely fast due to their superior design and low internal resistance. In addition, as quick as your amplifier needs a new current surge, your Rockville capacitor will provide it. This continuous cycle of power discharge and recharge guarantees flawless bass playback.