Solved the problem it was supposed to.
Crutchfield Customer Review (What's this?)
Not every install benefits from a capacitor. Mine did. Had wired my 1200 watt amp driving a single 10" with #8 wire. Had voltage drop/spike issues resulting in poor sound quality. Installed capacitor without difficulty. Straightforward. No problems. Stopped the twitch in my voltage and produced a notable improvement in sub performance which I could describe as tighter/cleaner bass. If your amp is starving for power momentarily as the music asks for high energy, this is a great solution.
Pros: Easy install helped by wiring options, kit includes resistor to charge and friendly hardware to make mounting easy.
Cons: The material of the outside of the capacitor containing graphics and brand is delicate and shreds when slipped in and out of mounting bracket. It is very easy to cosmetically injure this product.