Sturmey Archer Outer Dust Cap
Used in the following Sturmey Archer hubs: (and probably a lot more!)
Brompton Sturmey Archer 3 speed hubs:
Brompton Sturmey Archer BWR - Brompton Wide Ratio 3/6 speed hub
Brompton Sturmey Archer BSA - Brompton Standard Ratio 3 speed hub
3 speed hubs
Sturmey Archer AW 3 speed hub
Sturmey Archer S3X 3 speed fixed gear hub
Sturmey Archer S-RF3 3 speed hub
Sturmey Archer TS-RC3 3 speed hub
5 speed hubs
Sturmey Archer 5 star hub
Sturmey Archer 5 star Elite drum brake / hub
Sturmey Archer X-RF5 (W) - wide range - hub
Sturmey Archer S-RF5 (W) - wide range - hub
Sturmey Archer S-RF5 (N) - normal gearing range - hub
Basically this dust cap is used in most Sturmey Archer hubs
Sturmey Archer ref: HSA102