RD-R51M

For mega sprocket 34T

Tiny Front Derailleur    FD-R74S

For small chainring , 2x10  speed road bike.

Top Gear 36-42T.

Capacity 14T.

Tiny Front Derailleur    FD-R52S

For small chainring , 2x9  speed road bike.

Top Gear 36-42T.

Capacity 14T.

FD-R32-B

For double chainwheel max. 56T, total capacity 16T, rear 8 speed.