Tall wheels do NOT fit in all models of skates. These wheels should fit in just about ALL models of skates. Most outdoor wheels range from 78a to 88a.
Softer wheels stick to the ground better and absorb more shock but wear out faster.
Harder wheels last longer but can slide if you are not used to them. They also bounce more and transfer road shock directly to your legs. Wider wheels tend to last longer, drag more but offer more wheel to edge with. Wider wheels are found in hockey and aggressive applications. COREs differ by application.