Tough genuine Shimano tools
Used for re-aligning the rear mech hanger to maintaining precise gear shifting
Screws directly into rear mech hanger threads
Precision measuring ruler is pushed against the rear wheel at various positions to provide precise alignment info
The tool is used to gently bend the hanger for perfect alignment
Hardened steel for longevity and durability
See Shimano Spare Parts Manuals and Catalogues for full details and further information