The r780 rapidfire shifters are precise mountain bike style levers for road bikes fitted with flat handlebars and 10 speed drivetrainsmust only be used with fd 4600 fd 5700 and fd 6700 double front derailleursinstant 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 the speed of shift2 way release allows the upper shift lever to perform