What is the difference between a low-ported curb bit and a wide-ported curb bit?

Ok, so there are a few differences that i see in these. The first is on the wide ports the middle arch is wider and lower than the low ports. The low ports are way higher in the middle. Also, you can see in each of these pictures, when you clip the reigns on, they are each going to have a different pull on the horse's mouth. The first (the low port) is just going to rock back and forth in the horse's mouth. The second one (the first wide port) Is going to have a little bit more affect on the sides of the mouth. And the last one, well it seems the harsher of the three. It has a place for a curb strap to go, and the way that its angled, if you want the curb strap to say something instead of just sit there like they do on some bits.... it will! Also it will give you more control than the others. If your looking for something to just switch into for a little while to give your horse the experience, i would use either the first one (the low port) or the second (the first wide port). Like I said they are less harsh and would give your horse the experience you want it to get! Hope I could help! =D Good luck with the bit shopping!