Earthquake Sound MiNi D2500 Mono Class D Car Amplifier, 2500 Watts (Discontinued by Manufacturer) 2500-watt class "D" monoblock subwoofer amplifier installs Bridgeable In/Out to link two amplifiers together Highly efficient and compact for custom audio installs Automatic voltage protection circuit , variable LP X-over 0-12dB (30-80Hz) Bass Boost, plus Gain Control and Remote Sub Level