Aggressive Skate Frames - Buying Advice
Aggressive skate frames are universal in the sense that they use a two-bolt attachment to fit onto more or less any aggressive skate. You only really need to concern yourself with the size (and generally these will cover a few different sizes anyway, so there's not a massive amount of room for error).
There are a few different types of frames to choose from, depending on how you like to skate.
Anti-rocker frames are made to hold two smaller wheels in the middle (and they don't touch the ground)
No middle wheels at all
All four wheels touch the ground
Designed for a bigger wheels and faster rolling.