Strass I really don't know the difference between the two. I looked at them both at PetsMart but didn't take them out of the boxes. To be honest, I went with the Halti because it was a couple of dollars cheaper. I guess, like with anything else, if the dog is strong enough they could probably injure themselves but I really doubt it. I put it on Bella in the house for a minute or two before we went outside. Then when we were outside and the urge to pull was strong she knew that it wasn't going to be a good idea. I guess maybe it would be best to practice inside the house first before going outside. I'm not saying she loves it, but she tolerates it well. I am sure she would much rather be pulling me along down the street.