The L7R Square Sub moves more air, so you get more bass. The design was invented right here in Stillwater, Oklahoma – made to deliver unprecedented efficiency and huge volume! The engineers at KICKER invented the original square sub right here in the heart of America. Designed to give you more bass – yet take up no more air space – than a standard round sub. Welcome to the miraculous world of the L7R! Dual two-Ohm Voice Coil – Wrap Around Gasketing – Patented Ribbed Corners – Injection-Molded SoloKon Woofer – 360-Degree Back Bracing – UniPlate Back Plate And Pole Piece – Bumped Back Plate – Thick Tinsel Leads – Large Ceramic Magnet – Steel Basket With Spoke Design – Nickel Plated Speaker Terminals The L7R 15-Inch Subwoofer works best with a sealed or ported enclosure and 900 watts of recommended power. Size – 15″ (38 cm) – Rated Impedance – 2 Ohm – Sensitivity – 88.05 1W, 1m – Max Power – 1800 W – RMS Power – 900 W – Mounting Depth – 8 3/8″ (21.5 cm) – Mounting Diameter – 13 3/4 (34.9 cm) – Min Sealed Box – 1.5 cu. (42.48 L) – Max Sealed Box – 3.0 cu. (85.0 L) – Min Vented Box – 3.0 cu. (85.0 L) – Max Vented Box – 6.0 cu. (170.0 L)2.0 L.