The Swix Roto Double Brush is the most used wax brush in the World Cup. This Roto Brush features 70mm of Horsehair on one side and 70mm of steel fibers on the other. Swix recommends using the Horsehair side first and finishing with steel. The Horsehair side is used first to prevent the steel side from clogging up. Its is very important to deburr the steel lightly with 100 Grit sandpaper before using it the first time on skis. This brush is 140 mm wide and requires the 140mm drive shaft. 140mm Brush: 70mm Horsehair, 70mm Steel, Swix recommends using the Horsehair side first and finishing with steel., Deburr the steel lightly with 100 Grit sandpaper before using it the first time on skis, Shape: Roto, Bristle Type: Metal & Natural Fibers, Model Year: 2019, Product ID: 205768, Model Number: T0015HS, GTIN: 7045951083002