As expected, Sony launched a transmitting microphone and a receiver that fits into its complicated and delicate proprietary hot shoe. The ECM-W2BT(T) transmitter is small enough it can just clip onto a shirt pocket or collar, although it is longer than the popular Rode Wireless GO version, which was just updated. The equally-romantically-named ECM-W2BT(R) receiver is shorter, thinner, and longer.
Specs can be found here (thanks to nokishita)