Size:20 cm Type:Midrange Driver Maximum power:400 W Continuous power output:180 W Frequency response:45 Hz to 18 kHz Sensitivity:100 (1 W/1 m) dB Impedance:4 Ω Mounting Depth:78 mm Woofer Cut-Out Hole:Φ184 mm Woofer material:Paper Surround:Cloth Spider:Polyester Fibre Voice Coil type:Copper Clad Aluminium Wire (CCAW) Magnets:Ferrite Weight:4.7 (Pair, excluding accessories) kg Accessories:Speaker mounting screws.