New Rear Drums - Help with what size to order

[Yamariv]

Just about to pull the trigger on a set of drums from Rock Auto and am worried about getting the right size.

The ones I have chosen say 11x2", the other options don't say a size. I have the base model truck with a 5 bolt wheel and a 12 bolt rear end.

I've just removed a rear tire and measured across the front of the drum and I get about 11.75 inches. The drum depth is almost 4 inches.

Is this the right size to order? Or is the stock size the drums with no measurements in the listing?