Shimano SLX M670 10 Speed Shifters I Spec B Pair: The SLX M670 I Spec B 10 Speed Rapidfire shifters are tough, aggressive but light weight with Vivid indexing & 2-way release function. The 2nd generation I-spec-B design is developed to attach directly to I-spec-B brake levers. The 2-way release system allows shifting from various riding positions; the upper lever still performs the same shift function, but it can now swing in either direction allowing it to be released by the thumb or index finger. Tough, aggressive & light weight Dyna-Sys 10-speed shift levers Light to the touch but positive & crisp, Vivid indexing provides a constant amount of shift lever force across all 10 sprockets 2-way release function 3x/2x front shifter mode converter I-spec-B design is developed to attach directly to I-spec-B brake levers Multi-position adjustable handlebar clamp for custom lever positioning For use with Dyna-Sys 10-speed only Barrel adjuster for fine gear tuning Complete with inner & outer cable