This is a red band Bendix kickback hub, it starts out in 1:1 in the video and after the shift its in under drive (hub turns slower than the sprocket). Yellow band kickback hubs will act the same as this one, blue band hubs have an overdrive gear instead (hub will turn faster than the sprocket). If you notice the ratcheting sound when shifting that's the index spring turning to allow the gears to change.
![](https://i.ytimg.com/vi/BJKTKqMMdkY/maxresdefault.jpg)