The polypropylene woofer cone in the CSX-1400BP is engineered for superior rigidity, reliability and sensitivity The CSX-1400BP^s enclosure is vented, which enables the subwoofer to deliver ultra-low bass at higher sound pressure levels Featuring an acrylic window, so you can look into the enclosure and see what legendary bass looks like Orange LED lights within the enclosure. Visible through the look-in window, the LED illumination adds visual impact The rigid box keeps the woofer safe from anything that might slide around in your trunk