Installation was very easy. Disappointing but not a fail. I wear a 9 and ordered a 10 and my heel was hanging off the back. Was SO happy to find these for around $20, and I got tons of compliments all night. 2 more buttons than the previous model) that are permanently labeled, some of them for functions a user may only rarely, or never, use. Install is easy, so giving it 3 stars as they have not flown off or been ripped off in an automatic car wash. Con: it was UNBELIEVABLY hard to plug in anything. It is not too loud to use in the house where I have it set up. Boyfriend loves them, very comfy. Están hechas en China, son un sufrimiento usarlas, sin calcetines definitivamente no pude usarlas por 5 min, con calcetín trato de acostumbrarme pero no creo soportarlas una semana.