Park tool master link pliers mlp1 2many derailleur chains use a master link that allows the chain to be installed and removed by hand while this type of masterlink doesnt 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 buy park tool chain tools from chain