MODEL:TRF VL SW82 D2 SW82 D2 SIZE: 8inch CONE:competition grade paper SURROUND MATERIAL:foam VOICE COIL:2 inch RMS POWER:250 WATT SENSITIVITY:86.5db MAX WATT:500wmaxx RESORANCE FREQUENCY(fo):43.6Hz MECHANICAL Q FACTOR(Qms):2.65 ELECTRICAL Q FACTOR(Qes):0.6 TOTAL Q FACTOR(Qts):0.49 X MAX:9 mm FORCE FACTOR:12.1 N/A MAGNET WEIGHT:40 oz 1=Outer Dimension:213mm 2=Mounting Depth:100mm 3=Magnet Dimension:140mm 4=Mounting Hole Dimension:182mm