It’s high quality metal and there is no issues lining up charging components, you just sit it on. I just went to the dollar store and got a cheap little 5 dollar battery power bank and it works perfectly fine with it. These slippers are perfect for wearing inside and outside. If I only wanted to use my headphones for an hour or two per day, the Sony’s would win hands down (although I found them a little tight for my big head). Im very pleased w/ my order. I mean how hard is it to do induction charging. I have hand 5 plugs already fall apart. Favorite color too I was also impressed with the BlueAnt Pump Soul Bluetooth headphones, wearing this i feel dry and confidence.