The Mason Pearson Hairbrush cleans the hair and stimulates the scalp, increasing blood flow to the roots. -Pure Bristle brushes are ideal for fine to normal hair and fine long hair. -Boar bristle is used because it has a natural affinity to human hair. That is to say, the structure of Boar bristle is similar to human hair. The affinity makes the boar bristle cling to the hair shaft, to accomplish the purposes of hair brushing. -6 3/4 inches. About Mason Pearson: In the late 1800s, founder (and engineer) Mason Pearson introduced inventions that revolutionized the approach to making hairbrushes. Today, the unique rubber-cushion pad on each Mason Pearson brush is still made by hand and each handle is hand polished, using Mr. Pearson's original techniques.