Tamiya Modeling Brush Pro #00

From the manufacturer:
This is a high-quality pointed brush that uses Kolinsky Sable hair, the leading hair material for artist brushes. Kolinsky Sable hair has the favorable characteristics of being a flexible soft hair, that is also highly durable and naturally forms to a fine point, even after frequent use. The handle has also been carefully designed for an easy fit to reduce strain on the hand during long use. Perfect for excellent brush control, these brushes are recommended for fine detail areas such as vehicles and figures.