That is a proprietary plug for connecting the Furrion 95 watt "portable solar power charger", yours for only $499, available from Furrion. The connector is just a 10amp fused connection directly to your battery bank. This connection does not include a solar charge controller, it's only wire and a fuse. If you connect some other brand of panels to this, you will need to have a charge controller between the panel(s) and the connector.
I have contacted Furrion multiple times to see if a plug is available but have never received an answer. The only thing the connector does is allow Keystone to say our new Montanas are "solar ready". Nice advertising, but no real value as it is.
If you want to use your own portable solar setup, I guess you could change the connector out and reuse the wiring to the battery.
Dave, Barb, and Paisley the Wonder Wiemeraner
Was - 2015 3160RL Legacy Edition & 2014 F350 6.7l PSD SRW Platinum
Now - SOB