Models with enhanced, reduced or compressed textures and/or simplified structure, which are smaller in filesize and number of polygons than the original models (also by other modellers) for demonstration of efficient models at different Level of detail. Google recommends max. filesize of 500kB, max texture 1024x1024px, max number of faces 500. Models with over 10-20.000 polygons can't be shown on GE's 3d-layer. http://www.youtube.com/user/3dHH