The manufacturer does not give a recommended needle size nor a suggested gauge as this tightly spun yarn was originally designed to be used for weaving traditional Finnish rya rugs (ryijys), and not for knitting. It is perfectly suitable for knitting as well.
As it has usually been used for art textiles, Rya rugs, and the Finnish Crafts Organisation Taito’s DIY Rya kits, it has dozens of colorways that artists have requested over the years.