Quantum QB463 Beta Series 4 x 6 Inch 3-Way Speaker 4 x 6 Inch 3-Way Speaker, Piezzo Dome Tweeter, Mylar Dome Tweeter / Mid PP Cone, Ferric Oxide Magnet, Rubber Surround, Stamped Heavy Gauge Basket Max power: 130 Watts, RMS power: 40 Watts Sensitivity: 89dB, Freq. response: 75Hz - 25KHz Magnet size: 10 oz Ferric Oxide Magnet