I will be wearing them to the zoo. Batteries last for about 6 hours. They do have a sound to them when there is nothing attached and you are on the highway perhaps from the wind catching it. They are true to the size (I wear size 6M)! I prefer the size small I think, but medium works well too. I called customer service and was told it was just a “scrim” from the manufacturing process and it would wear off. Battery life - An entire days use on max volume for me. They are comfortable and stylish enough that I dont have to switch sandals when I step out for a minute. Ill be sticking to the "fur story" brand for their quality, for a slide that I can use more for running errands. I have used them with my Electric Guitar and BOSS Katana Mk 2 Amp and my VOX Blues Amp Plug.