Surly Track Cog - 3/32"

Surly Track Cog - 3/32".

Fixed Gear pinion of Surly, for 3/32 "chains
made of chromoly hardened
Fits on Formula, Dia-Compe Gran Compe-, among others Suzue hub

thread: ISO 1.375 "x 24 TPI
Surly says:
We choose ISO Threading (1,375" x 24 TPI), due to it ''s compatibility with other threads used on bicycle hubs.
ISO threads fit English and Italian threads almost perfectly.