The inside of the Medium Round Brush 33 mm is made of magnesium. The heat is retained and conducted better, which shortens the drying time. The brush has an anti-bacterial coating and is made of two high-quality materials that together form the best of both worlds: nylon bristles and cruelty-free wild boar bristles. The soft nylon bristles detangle the hair without damaging it. The boar bristles ensure that the hair does not become static, gives a lot of shine and makes the hair soft.