The KAC-9105D Class D Mono Power amplifier cranks out mega doses of power in a much smaller chassis size, so it's more adaptable to tight spaces like under seats or in trunks. The KAC-9105D also has a Dual Mono Drive connection that allows you to strap two KAC-9105D amps together to power a single subwoofer - that's 1800 watts of power!