Shimano deore m591 3x10 sptrigger shifterdeore mountain bike rapidfire shifter pods featuring 2 way release for cost effective dyna sys 10 speed shifting performancefeatures2 way release 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 fingerdyna sys 10 speed compatible for use with precision 10 speed mtb drivetrains pod design allows the use of these