KMC Z410-OL Half Link Connector
Make your bicycle chain perfect fit with this Half Link Connector.
This KMC Z410-O Half-link connector allows you to add or subtract half of one link (1/2 inch) from your bike's chain in order to optimize chain tension to get the best energy efficiency.
Remark: This item requires the use of a standard chain pin connector and chain cutting tool to install and connect.