Features:3 in 1 bicycle chain tool, used as bike chain wear indicator, also as chain hook and bolt measurement tool.304 stainless steel for rust-resistant, depolished surface for skid-resistant.High hardness for wearable and durable, high precision for accurate indication.As a chain hook for easy to deal with chain repair problems.Simple and quick to measure the diameter and length of bolts.Comes with hook for hanging to tool wall conveniently. Y13887