Update 2: it might also be compatible with Oculus Rift.
Update 1: now sold out!
TPCast claims there will be no noticeable lag from the adapter (less than 1 ms additional lag). Here is the wireless adapter in action:
The adapter will have a battery capacity of one and a half hours, but there's a larger battery available with 5 hour capacity. The larger battery is designed to be kept in a pocket.
The price is 1499 yuan, or about US $220. Unfortunately, it already sold out within minutes of it becoming available. It also won't ship outside of China.
TPCast's wireless adapter is the first wireless adapter for any of the desktop VR systems (including Oculus Rift and Playstation VR).