MiniMODS 2 to 3 Speed Sprocket Cog Set for Brompton Bicycle

1. 3 sprockets (12-15-17) or (12-14-17)
2. Spacer and C clip
3. Custom made 9 spline Shmano spec, compatible with Stock Brompton 2 speed hub and most third party external cog wheel mods (e.g. MiniMODs, Orz ... )
4. Not compatible with Sturmey Archer SRF-5 (W) 5 speed hub, but compatible with SRF-5(N) 10 (5x2) speed hub, so 5x3 is possible ... see photo below.
   
   Note: The black spacer should be put in between 17t and 15t (or 14t), 12t has built in extrusion rim underneath, so no need to use spacer.