The park tools mlp12 master link pliers are an updated version of the original and best selling master link pliers with many non shimano derailleur chains master links are used allowing the chain to be installed and removed by hand this type of master link doesn39t require a traditional chain tool but over time dirt and corrosion make it difficult to separate by hand the park tools mlp12 master link pliers has cleverly redesigned tips allowing them to be used to re join stiff or corrode