UltraTreez Desert Series ( Desert Olive 06, Desert Series ) including season changes, however now with No Snow Season as looks unrealistic. Naming of the UltraTree SpeedTree Content has (**,**). This helps seperate the old content from the Perfect Series Content, The Second Letter signifies Desert Series (D). These Perfect Series UltraTreez Product Line uses Mesh Library. Improved Billboard Visual Quality as well as improved Mesh/Texture Creation, and many other vast improvements not listed.