Many derailleur chains use a "master link" that allows the chain to be installed and removed by hand. While this type of masterlink doesn't require a traditional chain tool, over time, dirt and corrosion can make it difficult to separate by hand. MLP-1 Master Link Pliers make removal and replacement of these masterlinks quick and effortless. Simply insert the specially sized jaws into the masterlink and squeeze the handles.
This tool is a god send. Master links are supposed to simplify and make chain maintainence easy but I have always had a hard time disassembling my master links. Not anymore with this tool. Well worth the money.
Pros: Simple and straight forward.