Zipper seems weak, but it is actually very strong. Ordererd a uk men size 12 clog and received a uk men size 13. My Zolos had a light that flashed every few seconds but it was barely noticeable; these Panasonics light up an entire room, I’m not joking. Even other wireless ones are beating this weight by 20+ grams anymore. This excessive bass does an outstanding job of preserving the overall tonal balances. Very happy with this purchase so if you have a similar size to mine save yourself $10 and get them in big kid size. un-less the clothing is big. I recommend to anyone looking for an inexpensive (not cheap! The biggest concern I had for these slippers is that the fur would stick to my feet. I do like the mechanics of operation.