Without it, youre solely relying on the volume control of main device which I personally think can reduce the volume level to the output devices connected. The soles feel like small plush pillows in your shoes. I bought this wine rack to use in my apartment. Way to small cant even wear them size is small For me that kind of defeats the object of what I need for my "everyday cans". It wipes clean. I had to order TWO sizes down. Thank you for producing a decently made slipper at a manageable price. Bless you Keen! Im not too crazy about the disco type light effects, but since they can easily be turned off by pressing the pause button for 3 seconds, its irrelevant to my needs.