The Gentle Leader was the next
commercial head collar on the market. It tends to work better for
longer nosed breeds but works well on Rotts too.

Here
the Gentle Leader is seen from the front.
There is an adjustable
clip underneath the jaw so you can alter the fitting.
As with the Halti, you
should be able to put two fingers underneath (I prefer three) the strap at
the back of the head
Note that the side strap fits lower than the Halti |