SPECIFICATION:MODEL:TRF L SW128D1 Size: 12 Cone: Competition  Grade Paper Surround material: Foam Voice coil: 3.0inch Voice coil layer: 4layer Nominal impedance:dual 1ohm Voice coil wire:Coper RMS Power: 800wrms MAX Watt:1600wmax Sensitivity: 86.5dB Resonance frequency(f0): 35.8Hz Mechanical Q factor(Qms): 5.84 Electrical Q factor:(Qes):0.56 Total Q factor:(Qts): 0.52 Xmax: 15mm Force factor: 15..1N/A Magnet Weight: 110 Oz   1=Outer Dimension:  325mm - 12.8" 2=Mounting Depth: 155mm - 6.1" 3=Magnet Dimension: 176mm - 6.90" 4=Mounting Hole Dimension: 280mm - 11.02"