It is the Shimano 8 Speed Nexus. I really enjoy it...smooth as silk and silent. I love being able to shift at stops. The upper range seems to be a little low for me though. I think I may have problems spinning at high speeds, 30+mph (I have already hit 27 on flat ground and felt like I was spinning fairly fast in 8th gear). Then again, I am not usually traveling quite that fast, so it should be fine.