The Shimano Alivio SL-M3100 shift lever set is compatible with 2x9 speed drivetrains, and is great for entry-level mountain biking. The shifters incorporate Rapidfire Plus shifting technology for quick shifting, and also features Shimano’s 2Way-Release which allows for relief shifts by pull of the index finger or push of the thumb. The optical gear display window makes sure you always know which gear is selected.