The Boss Audio MR650 features an outboard crossover which is contoured on its inner surface to mount snugly and securely to the rear housing. Poly-injected cone with 1" aluminum voice coil. 1" mylar dome tweeter. Plastic grilles. 250 watts peak power handling. 4 ohm impedance. 60Hz - 18kHz frequency response. Overall: 7.76" dia. x 3.8"D.