I bought these for my dog, Koda, 2 years ago because her front paws have become sensitive to concrete/rocks in her old age. Without the boots on she limps a bit because the ground hurts her feet, but with the boots she trots along happy as can be! She only wears them on her front paws because her back paws aren't sensitive, so I've been able to use all 4 boots for her front paws. She is just now starting to wear through on all 4 of them, they've been awesome! She does trip on them from time to time when she's tired. but other than that we love them. Her old boots were gray but we decided to get the pretty "blue spring" color this time (^-^). She is a 60 lb boxer, her paws are 2.75 in wide, the medium's fit very well.
Pro tip! If your doggo rejects the booties at first, don't give up and try not to laugh. I found that when I laughed Koda wouldn't take the boots seriously. Take your dog on slower walks at first, be very encouraging and give treats!