The picture above shows examples of our 8mm Black Plastic Chain and 6mm Black Plastic Chain... below is a size guide for each.
 

How to assess the size of 6mm and 8mm Chains The 8mm Chain shown above has links which are approx 2 inches by 1 inch but because they overlap 2 links measure 3 inches.  There are 29 / 30 links to the meter. The 6mm chain shown above has links which are approx 1.5  inches long by .75 inch and because they overlap 2 links measure 2.25 inches. There are 40 links to the meter. .