This is the Shimano Alfine S505 Di 2 8 Speed Internal Gear 36 Hole Hub. New Deore LX component group is dedicated to trekking & is characterized by three keywords: smooth, tough & Ride Light, meaning "lightweight, compact & slim". This group offers gentle & secure feeling with stream design & strong reliability based on Shimano's proven technology. This 8 speed internal gear hub is only for use with the Shimano Di 2 shifting system. Featuring a wider gear ratio with lighter weight & a silent clutch. Gear ratio: 306%. Gear change support mechanism. Longer durability by oil lubricant.