These booties keep my baby's feet so warm.  They fit well, go on easily and stay on.  He can also walk around in them easily.  I purchased the 12-18 month size for my 13 month old and they fit perfectly.  They do get dirty pretty quickly, but that's to be expected with the light color.  There is no left or right boot and they aren't marked (believe me, I looked).  They seem to fit fine no matter which foot they're on.