RS, these are foam filled very light, very tough and rounder than most. I've got em on nearly every plane I fly, I had those Trexlers on my Big Mama and they are heavy. http://www2.towerhobbies.com/cgi-bin...&I=LXFV60&P=SM

Check out the Kavan's here they very cool looking even lighter than the Sullivans and tough too. http://www.hobby-lobby.com/wheels.htm