MB Quart FKB116 (2 pairs) Formula Series 6.5' 2-Way Coaxial Car Audio Speakers Power Handling: RMS: 60 Watts Peak: 120 Watts Impedance: 4 Ohms Tweeter Dome Material: Aluminum dome tweeters Speaker Surround: Butyl rubber surrounds provide durability and deeper mid-bass impact Cone Material: Lightweight thermal-formed polypropylene cones enable faster midrange response Surround Cone Coupling: The cone/surround connection utilizes a high temp adhesive which assure the cone and surround do not separate in high power uses or extremes of weather Voice Coil: Pure Copper Tweeter Size: 1' Frequency Response: 40Hz - 22kHz Sensitivity: 88dB