The Kicker C15-4 Subwoofer is equipped with double stitching on the surround, coil-cooling perimeter venting and ISD (Inverted Structural Dome). Highly versatile, it performs in free-air applications as well as invented or sealed boxes. The rigid cone's back bracing eliminates distortion, delivering a wonderful bass. Spiral tinsel-lead provides even more strength and durability. The ribbed surround, yellow stitching, nickel-plated push terminals and a basket design include a stylish logo trim ring. Xmax - 11.53 mm Top Mount Depth - 7-3/8 Cutout Diameter - 13-7/8