RaceWax Brass Ski Roto Brush 100 mm Interchangeable/Compatible with Swix/Toko/SKS/RedCreek brushes and axles. Select brass brush for before-wax base cleaning or for very hard waxes. See RaceWax Tuning Tips section for instructions. RaceWax Brass Ski Roto Brush 100 mm 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. Interchangeable/Compatible with Swix/Toko/SKS/RedCreek brushes and axles. See Product Use tab below or Tuning Tips section for instructions.