One of the boards on display is the watercooled X499 AORUS Xtreme Waterforce, this one looks pretty expensive!
So there will be three motherboards from AORUS that will be part of the X499 platform. These include the X499 AORUS Xtreme Waterforce which is a high-end model that makes use of a very enthusiast-specific design and even comes with AORUS’s own water block that extends from the CPU and down to the PCH and the M.2 slot. AORUS is using a very beefy 16 Phase VRM on the motherboard itself and makes use of dual 8 pin connectors to power the CPU socket.