3/32 is the road/mtb standard. 1/8th is the bmx/track standard. What is your fixed side? If it's 1/8th get a 1/8th freewheel, if it's 3/32 get a 3/32 freewheel. You can use 3/32 cogs with 1/8th chains, also.
@hippy started
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3/32 is the road/mtb standard. 1/8th is the bmx/track standard.
What is your fixed side? If it's 1/8th get a 1/8th freewheel, if it's 3/32 get a 3/32 freewheel.
You can use 3/32 cogs with 1/8th chains, also.