General Features: 4x6 (10 x 15cm) 2-Way Coaxial Speakers Carbon Mica Cone (Strong Bass) Hybrid Surround (Strong Bass) Stamped Steel Frame: Yes Strontium Ferrite Magnet: Yes Tweeter Size: 1 Poly-Ether Imide Balanced Tweeter Neodymium Magnet Frequency Response: 55 - 25,000Hz Power Handling Capacity (RMS): 20W Power Handling Capacity (Peak Power): 140W Impedance: 4 ohms Sound Pressure Level: 85dB/W.m Weight: 450 g Magnet Mass: 5.4 oz (153 g) Mounting Depth: 1-25/32'' (44.8 mm)