All pics show are the Vent Cap, which is the exhaust and the inlet air cap. What is used for a RAINCAP?
There is no rain cap with this type of vent termination. "Why not?" you may ask?
The exhaust piping from a condensing appliance is designed to carry liquid. The appliance category is named "condensing" because these appliances extract so much heat from the exhaust gas stream that the water vapor condenses to liquid on the walls of the exhaust (vent) pipe.
It's ok if some precipitation enters the vent pipe because the pipe is liquid tight and is designed to drain these liquids back to the appliance itself. The appliance has a drain hose and sometimes a pump to remove these liquids out to the building sanitary sewer system. Clearly this arrangement can't handle the volume of water that a plumbing vent could, but it is sufficient to handle ordinary condensate and weather volumes.
The vent cap of the concentric vent, or a down-turned elbow in a two-pipe arrangement, sheds precipitation so that the combustion air inlet remains dry.