ID8 V.4 D4 - Image Dynamics 8" 350W RMS Dual 4-Ohm ID V.4 Series Subwoofer Power Handling: Peak: 700 watts | RMS: 50-350 watts Top-mount depth: 4.75" | Cutout Diameter: 7.125" | Sensitivity: 85.4dB Stamped steel basket for improved rigidity and better power handling T/S Parameters: Re: 1.95/7.8 ohms | FS: 24.7 Hz | Qes: .367 | Qms: 3.572 Qts: .332 | Vas: 1.55ft3/44 L | Xmax: 15mm | Sd: 231 cm2