With WI you can change the worn part (I think that's called the 'outer gear case'?). I'm not sure any other freewheel allows that.
The only place I know which sells WI spares is CtBM, and he does it by dismantling freewheels, rather than getting packaged spares, so they're not (afaik) returnable.
@miro_o started
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With WI you can change the worn part (I think that's called the 'outer gear case'?). I'm not sure any other freewheel allows that.