Shimano tiagra 4600 2x10sp flat bar shifterthe tiagra sl 4600 rapidfire shifters are precise mountain bike style levers for road bikes fitted with flat handlebars and 10 speed road drivetrainsfeatures must only be used with fd 4600 fd 5700 and fd 6700 double front derailleurs instant release for super fast shifts delivering the chain to the next gear the moment the lever is actuated with no hesitationmulti release allows multiple gear changes from both levers with one sweep further adding to