Sometimes simple things are better. No matter what kind of riding you do, or what kind of drivetrain you&';re using, these retro-futuristic friction left thumb shifters deliver an intuitive, straightforward user experience. Whether you&';re touring remote wilderness areas or riding around the neighborhood, you won&';t miss a shift Friction left side shifter compatible is with MTB double and triple front derailleurs Innovative torque bolt allows shift effort to be adjusted Low profile CNC machined aluminum body 22.2mm bar clamp diameter Double or Triple: Both Shifter Style: Thumb