Also PC Btw, with singstar clone-like as Performous, or Vocaluxe UltraStar DX, or any audio recording software, just understand that the microphones are connecting has a unique channel (Both microphone are mono, USB receiver merge the signal to the stereo, taking the microphone to the left blue and red microphone to right)
PS: shipping costs are not account 15E of the rule does not appear to be absolute.