He didn't mention the knot size or anything like that. I asked but he was unsure whether the brush hair was classified best, premium etc.

As far as what I can see it is a fairly large knot. The bristles fanned out to about 2 inches and about an inch if held together. The brush was extremely soft at the tip, and seemed not stiff in the body, but not like it was falling over either, medium on that I would say. It didn't lose much hair, and did lather very well as far as we could tell. Overall the craftsmanship is superb. The brush is very solid, well made and wonderful to hold and behold. This guy knows how to make a quality brush. No blemishes.