RaceWax Wide Ski 150 mm Roto Brush Brass 150 mm Perfect for wider Alpine skis. Use the brass brush for before-wax base cleaning or for very hard waxes. Use in a tail-to-tip direction for base structure renewal and pore opening for better wax absorption. See Product Use tab below or Tuning Tips section for instructions. OK to use two 150 mm brass brushes together on a 300 mm axle for snowboards.