It is a dual wheel setup.
It was described to me before I bought it as something to protect the deck while going over curbs, they mount in the center rear.
The wheels are really wide, maybe 6 inches or more?
I don't know why they don't just include a full width striping roller like my Z2.
It does the same thing and stripes the grass.
Remembering all my departed friends.
Well, I hope everyone is happy now.