This is the Honda EU1000 parallel cable
Note that they say when you use it with two EU2000s, you only get 20A (2400W), not 33.3A (4000W).
As I note in my webpage
, 20A is the rating of the circuit breaker on the EU2000 duplex outlets, and is all you can get from a 20A outlet when using the EU1000 cable between two EU2000s.
To get the full output, you must connect each generator to a 30A travel trailer outlet.
One guy on iRV2 bought one of those EU1000 cables, cut it, and then wired the cut ends to a 30A travel trailer outlet, so he didn't have to mess with the banana plugs like I did.
The only thing I'm concerned about is the capacity of that EU1000 cable. When used with two EU1000s or with two EU2000s for 20A, the most it has to carry is 10A. When it is carrying the full output of an EU2000 to a 30A plug, it can be carrying as much as 16.7A. I chose to use 12AWG cable and do the banana plugs manually.