A chain tool is a small mechanical device that " breaks" a bicycle chain to be mended with the same instrument. A bicycle chain has links and plates pinned together; these pins can be pushed out with the chain tool.
Link 11 Folding Chain Tool Compact, foldable, and high-quality metal chain tool for single and multi-speed chains up to 12-speed, including Campagnolo® hollow pin chains. Included chain hook holds links...
All Speeds Chain ToolHigh-quality chain tool with replaceable plunger pin for single and multi-speed chains up to 12 speed, including Campagnolo® 12-speed hollow pin chains. Included chain hook holds links...