This is it: my favorite. I have bought three sets of this unit. It works well and I have nt had any problems over the years. It includes a lavalier and an interview mike, plus battery-powered (AA) transmitting and receiving units.
According to my audiophile friends, this is the best low cost option for an external USB microphone to use with a laptop in any number of situations to get high quality audio for my Google+ Hangouts On Air.