BOSS Audio Systems AR4000D Armor Series Class D Monoblock Car Amplifier - 4000 High Output, 1 Ohm Stable, Low Level Inputs, Low Pass Crossover, MOSFET, Hook Up To Subwoofer For Bass Kick your Bass into high gear with the Boss Audio Armor AR4000D Class D Monoblock Amplifier. This powerful 1-Ohm stable Amplifier features 4000 Watts Max Power with a MOSFET power supply to get your tunes rocking. Customize the sound with Variable Low Pass Crossover, Bass Boost and Subsonic Filter. Maximize the Bass with the Remote Subwoofer Control. For double the performance and power, strap on another AR4000D for a total power of 8,000 Watts @2-Ohms. The Armor Series of Amplifiers packs incredible power and performance into a feature-rich slim design for put-it-anywhere convenience. Give power to your playlists with the Boss Audio AR4000D. Class D Car Amplifier - 4000 Watts, 1 Ohm Stable, Digital, Monoblock, Mosfet Power Supply Ramp up your vehicle's Bass with the BOSS Audio Systems AR4000D Class D Monoblock Amplifier. With 4000 Watts Max Power and MOSFET power supply, this Amplifier packs an audio punch. Customize the sound with Variable Low Pass Crossover, Bass Boost, Subsonic Filter and Remote Subwoofer Control. Strap this Amplifier to another AR4000D for double the performance. The Armor Series of Amplifiers packs incredible power and performance into a feature-rich slim design for put-it-anywhere convenience.