Alcon 0.875" Pivot-Mount Master Cylinder: Gold Nut vs Red Nut
Short answer: The Gold Nut (MAR5240HM161MBB) uses a 3/8”-24 UNF outlet port, making it the right choice for North American race builds plumbed with standard AN or UNF brake line fittings. The Red Nut (MAR5240HM161MAB) uses an M10×1 metric outlet...