Massive Audio HIPPOXL122 4000 Watt 12" Dual 2 Ohm Car Subwoofer Heavy Duty, Rugged Industrial Textured Cast Aluminum Basket 350oz High Energy Double Stack Strontium Magnet Structure Dual Impedance Black Anodized Voice Coil Former with Kevlar Spunlace Kevlar Fiber Reinforced Non-Pressed Paper Cone with Industrial Textured Finish Red Stitched Edge to the Cones Edge for Added Strength Over Sized Mirror Image Dual Poly / Nomex Spiders Black Anodized One Piece Pole-Plate for Added Motor Force Heavy Duty Direct Input Wires Connection to Voice Coils Reinforced Fiberglass Woven Dust cap for High Power Applications Custom Tooled Rubber Gasket and Magnet Boot