I purchased this shoe in both 3-6 months (for my niece) and 12-18 months (for my nephew). I was looking for a shoe with a soft and flexible sole because research has found that hard soles are not good for babies' development. These little shoes are so adorable, good quality and they are super easy to slip on baby's foot.<br /><br />The outside of the shoe is a leather-like material and the inside of the shoe (the insert and toe box) are terry cloth (similar to an infant wash cloth). The insert is soft (for the bottom of baby's foot) and has a good cushion. The sole is a flexible &#34;suede-like&#34; material, allowing for proper growth and foot formation for baby.<br /><br />An elastic band around the &#34;ankle&#34; of the shoe expands and contracts with ease, making it a breeze to slide the shoe on and keeping the shoe on baby's foot. My 13 month old nephew wore the shoes and walked around (even on carpet a linoleum) with no issues. He seemed comfortable and the shoes seemed to support his balance. However, after wearing the shoe for some time and removing the shoe, I noticed a slightly red imprint on the top his foot from the elastic band. I do not think the elastic band hurt him and it did not cut off any circulation.  He was wearing the 12-18 month shoe. I will update this review once I am able to try the 3-6 month old shoe on my infant niece (she's currently too small).<br /><br />Please note: I received a discount on this item in exchange for this review. However, this review rating and the entirety of it's content is 100% mine. This review was written with an unbiased and honest opinion. If you find this review helpful, please be sure to let me know by clicking &#34;yes&#34; this review was helpful. Thank you.