Sturmey Archer Single Speed Freewheel Cog - 1/2 x 1/8" or 1/2 x 3/32"
Compatible with 1/2 x 1/8" and 1/2 x 3/32" chains. Cog Sizes Available: 16t, 17t, 18t, 19t, 20t, 21t and 22t. We will endeavour to turn an unhappy experience into a positive one. Colour: Silver. Thread - BSC 1.37 x 24 tpi.