If you are looking for Aurum Cantus ribbon tweeter quality in an easy-to-mount format, the APR2.1 is what you need. Its outstanding accuracy and extended frequency response are identical to the rest of the Aurum Cantus tweeter family, but now in an easy to flush mount version. Good partner for a single high efficiency midwoofer. Hand-made aluminum foil planar hexangular honeycomb diaphragm. Specifications: *Power handling: 30 watts RMS/45 watts max *Impedance: 6 ohms *Frequency range: 1,700-30,000 Hz *SPL: 92 dB 1W/1m *Recommended minimum crossover frequency: 2,500 Hz *Dimensions: A: 4-5/16", B: 3-3/16" x 2-3/16", C: 3-1/4".