Industry standard locomotive Delrin chain set.
This is the same Delrin chain and gears we use in our power bogies. Delrin has been used in model locomotive applications for 10's of years and is known to be perfect for the job of transferring drive from one axle to another. This set comes with a pair of push fit 10 tooth cogs and a 6" length of chain.
The cog bore is 3/16 (4.8mm) and the cog diameter is 11.5mm. The chain simply unclips and reclips and can be added to or made shorter.
Chain 6" (150mm) long
Cog 11.5mm diameter
Cog bore 3/16" (4.8MM)