Dont know what kind of alloy/materials theyve used, but its definitely cheap if it breaks after less than a month of usage. The only I gave them a rating of 3 is that I just recieved them and really dont know how long they will last. BUT THEY STILL HURT! I had to go to the store and buy a basic ratchet with that size to finish the work. I spent an entire day in front of a committee with my left sock bunched under my toe because it wouldnt stay on. I just love these shoes as they are extremely comfortable as a walking shoe. For the price, I had hoped theyd be excellent. ) Their site does not work and you cannot get drivers. When the box arrived in my front porch it looked well packaged. We have taken this to the beach (it’s waterproof) and entertained everyone within 50 yards from us (be sure to download the JBL app) when put on outdoor mode.