Shipping Information This item weighs 3.5 kg 12" 30 cm subwoofer mac Audio Mac Nitro 300 II , MAWS 300 CP 4120 I 12" inch (300 mm) subwoofer, 400 watts max., 91 dB.  With the Mac Nitro series, the name says it all. Ideal for Reflex incl. integrated protective grille.   The highlights: Stable, torsion-resistant sheet steel basket Thick pole plates Stable connections Stable cone diaphragm Durable resonance-free rubber surround Polycotton centering spider Deep-drawn yoke Good efficiency TOP brand quality Data sheet Manufacturer's specifications Type designation Mac Nitro 300 Manufacturer / Brand mac Audio Usage Subwoofer Outer diameter 307 mm Installation diameter 278 mm Installation depth 110 mm     Coil diameter 50 mm Magnet diameter 110 mm Music power RMS / Max. 300 / 440050 Watt Impedance 4 ohms Resonance frequency (FS) 35 Hz Efficiency 91 dB/1W/1m Total quality (QTS) 0.45 Equivalent volume (VAS) 90 l Linear excursion (xmax) +/- 10 mm The data has been determined to the best of our knowledge and belief, but due to the amount of data and possible measuring, reading or typing errors, we cannot guarantee its accuracy<br>< BR>