Hi Tommi,
In fact I didn't ask for the Rocna like for the Viking but I'm copying their answers which they allow me to publish:
"Viking Anchor
When using this type of anchor, we recommend using the "Single roller", not the "Pivoting bow roller".
See the difference between the variants when toggling the options on the product page (link above).
The reason for this is the arch or handle on these types of anchors.
We have not tested the Viking anchor specifically. However, we have tested the Rocna Original 25kg and 33kg variants.
It´s also worth mentioning that our cassette or hook ladders cant be mounted on the bowsprit when choosing an anchor with an "arch/handle"."