Heavy-duty die-cast basket with black power finish
Black non-press paper composite cone
Hi-roll high-density Ribbed foam surround 
4″ hi-temp 4-layer flat aluminum wire voice coil on aluminum bobbin
4pcs double black poly-cotton spiders with the mirror-image layout
Spaced by spider ring,double-thick tinsel stitched on spider
Triple stacked 402oz magnets(each magnet size is 3X254x20)
1-pc technology T-yoke for maximum excursion
Carbonized dust cap
Voice coil direct cooling design motor
10-gauge pure copper power cable for direct connecting
Rubber gasket and rubber magnet boot
Dual 2ohm impedances
3000W RMS power,6000W Max power
Packing:each sub is packed by polyfoam+inner box