The lever also includes Shimano’s optical gear display, which shows riders what gear position is selected while riding.
The Shimano Nexus SL-3S41E Switchbox with integrated Click Box is the add-on for your 3-speed internal rear derailleur bike.
It is compatible with several Shimano Nexus internal gear hub models, including the SG-3R40,
SG-3R40-DX, SG-3C41-DX, NEXUS INTER-3 SG3C41 and SG-3D55.