VihtaVuori is a Finnish Powder Company that has been manufacturing powder since the 1920's. VihtaVuori powders are extremely popular with benchrest shooters, High Power shooters, and varmint hunters.
This is a moderately slow burning powder that can help refine cartridge ballistics when N140 is just a tad too fast and N160 is a tad too slow. Works well in many applications.
Sinclair, Issue:3B, Page:096