harley 4dTECHNICAL SPECIFICATIONS. 1200.4D 2Ω Power @ 12.6V @ 1Ω: 4 x 300 W RMS Power @ 12.6V @ 2Ω: 4 x 165 W RMS Power @ 12.6V @ 4Ω: 4 x 91 W RMS Bridge Power @ 12.6V @Shop the Official Harley-Davidson site for new & used motorcycles, genuine parts & clothing. Locate a dealer or sn up for a test ride.