This Maillard “MD” cog fits Maillard 700 course 5 speed body series freewheels in smallest position, as well as the Helicomatic 5 speed in the smallest position. Also a perfect substitute for the SACHS FY cog. Silver finish. Also fits by design the Helicomatic 5 speed freewheel. Maillard intentionally did this.
This cag is a duplicate of the ARIS “FY” cog having the same index Y-tooth profile.