The Red Clix RX35 drivetrain set is an upgrade for Comandante C40 coffee grinders that offers twice the number of grind settings for greater precision. It features a finer, more responsive click mechanism (15 microns per click versus 30 microns for the standard axle) for precise dialing in, especially for espresso. the set includes the Red Clix axle, a special red grind dial, and matching ball bearings and washers for easier installation.