A-OL100H-AI 100 Hvy Offset Link (USA)One New Aftermarket Replacement #100H Heavy Series Roller Chain Offset Link This #100H heavy series roller chain offset link (also called a half link) is used to add an additional link to a strand of #100H heavy duty roller chain, or for making miscellaneous repairs when a chain requires an odd number of pitches. It is made from carbon alloy steel and conforms to ANSI B29. 1 standards. The heavy series features thicker side plates compared to standard