The Kappa 1000W 10" Subwoofer features the exclusive Selectable Smart Impedance Design, allowing you to build exactly the system you want, high-power or multi-sub, without complicated wiring. Just flip the convenient impedance switch to choose safely between 2 or 4 ohms If you're looking to upgrade your amp or add another subwoofer later, this subwoofer is easy to reconfigure and almost impossible to miswire..PZA MORE SPECS