Wire Gauge

Did a little searching on here and didn’t see anything pertaining to what I’m looking for so here we go.
Recently replaced my battery and cleaned my terminals up with a wire brush but they are just a bit too corroded. So I need to replace them BUT I don’t want to cut the positive side cause there’s not enough slack. I figured I’d extend the line but idk the gauge… anyone know what wire gauge the positive is? It looks like 4 or 6ga but want to be sure.

unfortunately I don’t have any stores that carry anything larger than 8ga around me to compare to.

 

Amazon, order whatever length/gauge you need, you’ll need the lugs/terminals separately.