A. 2.0 stereo speaker with FM/USB/SD B. digital FM, 20 memory stations C. perfect for stage, karaoke, party, etc. 2.0 stereo speaker with FM/USB/SD1. Power (RMS): 55W*22. Impedance: 4Ω3. Speaker units: 10" + 10"4. FM, 20 memory stations 5. USB/SD 6. protection circuit7. dimensions: 33.5cm×29.5cm×50.5cm ×28. packing dimension: 65.7cm x 37.5cm x 55.5cm