Designed to work with most bicycle chains for pressing out the links to lengthen or shorten your bicycle to fit multiple cassette configurations Shop-quality chain tool for most chains single to 11 speed Helps in retracting pin guide supports and guides chain pin out of link and prevents damage and misalignment to the chain Guide pin sheer slot for a clean break This tool is for Shimano type HG/UG/IG chains and fits 8/9/11/12 speed cassettes. CHAIN BREAKER TOOL