Its also hidden in the specs what the USB ports will power. Missed return window, (they were a surprise so they’ve been in the closet for months), so I guess I’ll have to try to replace the elastic and hope my son’s feet stretch the fabric. I have gotten my complements on them. The products are a very good concept and quality, but I think maybe the seller should provide more size that larger shoe size can actually use for their whole shoe. Super comfy and have a wide fitting - I would recommend they are worn with socks in the house for the first wear as they arrived misshapen from transit which is soon rectified with wearing. The shoes are very light and look beautiful but are agony to get on. They can also be washed in the washer and air dryed in case they need it. These are amazon for the price! Wish I would of ordered more than one. We get to our destination and everything in our bag is SOAKED.