The Knotty Cedar used in Dundalk Saunas is usually from smaller trees or the top of trees where there are more branches that create the many knots you see in the wood. This is just a characteristic some people like in the wood of their sauna.
The Clear Western Red Cedar is from the west coast of North America and has fewer knots in the wood.
These are the same type of wood, but with a different characteristic; more knots vs fewer knots.