The Dr Bristol is very similar to a French link as a Dr. Bristol also has a flat plate in the middle of the mouthpiece to reduce the nutcracker action on the horses tongue. With a Dr. Bristol, however, the flat plate sits at an angle to that it applies more pressure to the tongue than a French link.
A Dr. Bristol is a good choice for a horse that does not tolerate a single-jointed bit but who can get somewhat strong.
5" is an Elico Bit