Sorry I didn't see this a while ago. I made mine for about $30. Real easy to make with two 20 amp plugs two 3 foot pieces of 12/3 SO cable (standared 12/3 cord) and one RV repair plug. It's not UL listed but if someone is messing with my gens, they get what they get if they mess up. They better hope they don't yell to loud or they'll have to deal with the owner, and that will be worse than a little 120.
Only thing that has to be done is it needs to be pluged into both gens before you start them or you will have a live male end. The $250 version has no chance of this, since both plugs are shielded.
04 Mandalay 40B, 2014 Jeep Unlimited toad, Aladdin tow bar, Roadmaster 9160 braking system.