"I guess the manufacturer should have included directions, because it seems that other reviewers are having a difficult time figuring out how an H-harness works.
My only complaint is that there is no pinch clip on the part that goes around the animals neck. Basically, this means that you will always have to adjust the size of the neck hoop and make it bigger to comfortably put it on your pet (over his/her head.) Then you have to tighten it once it's on him/her. A bit of a pain. But otherwise, it's a nice little harness that works as intended.
The belly portion easily adjusts up to 13.5 inches. 14 inches might be a little snug. The smallest I can get the belly portion is about 9 inches. Same for the neck portion - 9 inches is the smallest it will go, 14 is the largest. Any reviewers who suggest otherwise are doing something wrong.
If you think you may have difficulty with this harness, I'd suggest a figure 8 style instead."