Shimano alivio m4000 9 speed trigger shifter setalivio mtb dedicated mountain biking components rapidfire plus is suited to quick shifting giving riders the ability to downshift three gears in one stroke rapidfire plus shifters all feature 2 way release which means release shifts by pull of the index finger or push of the thumb proven race technology with larger clearances improved ergonomics and a visible optical gear display to confirm the gear position at a glance features shift lever