there actaully 4 differant types of TA wheel , but the one you are talking about was mainly designed to be used with AVRE,S, Bridgelayers ,ARVs and other variants due to the strain put on the front wheels when dozeing etc.
ther are same size as a normal wheel but bigger then chieftain, outer rim is wider then inner rim.
the wheel can be seen being used by alot of nations mainly those with modified chassis ,
hope this helps
ossie