loudspeaker ,pro speaker good value for money ,low compenent,high quality RX22;Throat Diameter : 0.86inMouting Diameter : Screw onNorminal Impedance : 8 ohmsPower Capacity : 80w Continuous ProgramSensitivity 1w/1M : 107dBDiaphragm Material : Titaniumvoice coil material : copper clad Aluminium Flat wire compression driver RX22