Flat ‘C’ Chains C-40 (1.2 mm – 1.8 Gr./Ft.) C-50 (1.5 mm – 2.5 Gr./Ft.) C-65 (2.0 mm – 5.1 Gr./Ft.) C-85 (2.6 mm – 8.2 Gr./Ft.) C-100 (3.0 mm – 10.9 Gr./Ft.)