Do cultivators, tillers and rotavators have variable tilling widths?

Some do but it's fair to say that most cultivators, tillers and rotavators have a fixed tilling width, and generally the smaller electric machinesdo not have a variable working width. 

However, a few of the larger and more comprehensive petrol front tine tillers have variable tilling widths. 

The way this works usually is that you can remove outer tines so you can reduce the usual width and narrow the working width to, for example, work between rows without causing damage.