SKS Chainblade Black (Max 42-44 Teeth) Hub/Derailleur Gears:

The innovative, lightweight Chainblade system includes a telescopic function, adaptable to the length of the rear chainstay, + / - 125mm

Constructed from aluminium, plastic and zinc plated high quality steel, in a smart matt black finish, 3 versions are available for different types of gear systems.

Suitable for hub gears or derailleur gears, crankset must include a chainguard ring; max chainring diameter 175mm / 42-44 teeth