Lanzar Distinct Series 18" Inch Car Subwoofer | Free Air DVC Pro Audio Car Sub | 18 -In. 600 Watt (DCTOA18D) 18 INCH SUBWOOFER: Lab Tested Pro Audio Car Woofer Performance - IB Woofer Speaker Sub Sound Drive Unit HIGH-POWER CAR SUB: Power Output: 600 Watt MAX (300 Watt RMS) - 4 Ohm Impedance DVC VOICE COILS: Dual Voice Coil Car Speaker Design - Barium Ferrite Magnet - Stamped Steel Basket INFINITE BAFFLE AUDIO: - Open Free Air Car & Truck Speaker Enclosure Box Panel Mounting Compatibility SIZE / MOUNTING: Car Sub Size: 18 In. - Total Size (Diameter x Depth): 18.11" x 7.95" -Inches - Mounting Size (Diameter x Depth): 16.14" x 7.33" -Inches