Special Roto Brush set. Consisting of RB30 - Handle for roto-brushes 200mm with plexiglass protection shield, assembled on ball bearings and with safety, anti-slip grip. RB 17 - White Nylon 10 mm. Very soft bristle for working on low melting point waxes. RB 19 - Horse-Hair-Bronze 10mm. Recommended for finishing waxes with a high melting point. For correct use of roto brushes we recommend to not exceed 500 RPM.