With Di2 technology shifting is easy and precise - just a light touch, as soft as a mouse click, is sufficient for the front or rear derailleur to instantaneously select the correct gear.Key Features:The removal of traditional mechanical cables in favour of electrical wires eliminates poor shifting caused by contaminates, corrosion and stretching, and also gives effortless gear shifts,Shimano's FIREBOLT customizable shift button placement has been designed entirely by human ergonomics, this means the shift buttons now sit exactly where your thumbs naturally sit,Shifting can now happen as quickly and effortlessly as possible thanks to the super light Short-stroke lever, giving you more time to adjust to the trail ahead,Shifter is completely customizable, using E-tube software you can programme the shifting to your preference,Synchro Shift compatible meaning both front and rear shifting can be achieved through the use of just a single shifter,Left or Right hand band clamp mount type,For use with E-tube electric cables.