These shoes have an adjustable elastic giving extra room to grow. All booties 6M+ have a non-slip vegan leather sole. Booties under 6M have a soft sole.
For the best possible fit with extra room to grow, I recommend measuring your little one’s sole and adding .5 - .75 inches to that measurement to pick the best size. If you go too big, they won’t stay on. There is some stretch to these as well!
These are lined with a light cotton jersey fabric.