Kenwood Excelon X501-1 Mono subwoofer amplifier &mdash; 500 watts RMS x 1 at 2 ohms + Amplifier Kit 8 MONO SUBWOOFER AMPLIFIER: Kenwood Excelon X501-1 Mono subwoofer amplifier  500 watts RMS x 1 at 2 ohms mono subwoofer amplifier, 300 watts RMS x 1 at 4 ohms (500 watts RMS x 1 at 2 ohms, CEA-2006 compliant, Class-D amplifier design, variable low-pass filter (50-200 Hz at 24 dB/octave), bass boost (0-18 dB at 40 Hz), frequency response: 20-200 Hz preamp and speaker-level inputs, fuse rating: 30A x 2, 8-gauge power and ground leads recommended  wiring and hardware not included with amplifier, 6-11/16"W x 2-3/16"H x 7-3/8"D AMPLIFIER KIT 8: (AMPLIFIER KIT) (1)17Ft Blue Power Wire4 GAUGE, (1) 15Ft. RCA 4 GAUGE, (1) Purple/Black Ground Wire4 GAUGE, (1) OFC Speaker Cable 12 GAUGE, (1) BLUE Remote On Wire 16 GAUGE, (1) Wate Resistant Inline Fuse Holder AGU Type 4 Gauge, (1) AGU Fuse 80 AMP Gold Plated, (1) Gold Ring Terminal 4 GAUGE, (1) 6Ft. Split Loom Cable Protection, (4) Female Disconnectors, (2) Ring Terminals, (3) Self Taping Screws, (1) Rubber Grommets, (1) Pack Cable Black Ties, (2) Small Butt Connectors, (1) Large Butt Connector CUSTOMIZATION: CHOOSE YOUR FREE HEADPHONES ( 1 PAIR FREE HEADPHONES: Frequency Response 20Hz-20kHz, Sensitivity 110dB, Cord Length 1.2 M. Exceptional sound for any ipod or mp3 player.)