You are buying Exact plant #14 Overcup oak or Swamp Post oak (Quercus lyrata) bare root 3 Year Old, dormant, bare root.

Delivering it with roots wrapped in wet media during dormancy (October-April), in container with soil May through September. It is recommended to pot it or plant it in open ground promptly as you receive it (dormant plants). 

Keep roots moist all the time. Plant will be sent secured in the box. It has developed good root system and ready to be transplanted to the permanent location. See the pictures autumn color and shape of the leaves.