The Efneo GTRO Gearbox is a 3 Speed Internally Geared Crankset
Replacement. It will give you an effective gear range identical to
having a 28/40/50 Triple Crankset up front, without having to use a
front derailleur. You can shift the Efneo whether you are moving or
standing still! The Efneo GTRO Gearbox comes in 3 different
configurations- Twist Shifter, Trigger Shifter, or Bar End Shifter. For
more information visit www.efneo.com