Our Kicker subwoofer packages include one or two Kicker subwoofers and a Kicker amplifier that will provide enough RMS wattage to power them. We offer these packages in a single woofer, dual woofer, and loaded enclosure configurations. The single and dual woofer packagesare perfect if you already own a subwoofer box or if you plan on building a custom box yourself. If you don't have a box and you do not want to mess with building one, the Kicker loaded enclosures are perfect. They are pre-wired to 2 ohm impedance, they provide the correct amountof air space, and they are strong enough to withstand the force of the Kicker woofers.