They look a little higher than a FFP 187.
There are 3 versions - straight and spin and one which the manufacturer claims to be a bit rubberised (for durability). The foot is straight - no helical and you won't be able to fletch them helical as they are very stiff/brittle. You can fletch them with a little offset.
Almost every archer I know in my neck of the woods have given up on them as they get damaged faaaaaaaaaar too easily and as such, are very expensive. They are also very critical of set-up.
Hope this helps.