These are cross-strap sandals for indoor use. The material is linen on the sole, so I think it won't get sticky even if you sweat. They are very light♪ The product tag says the size is 27-27.5cm, but... there's a number 290 on the back of the sandals! I bought them based on the tag, so no one in my house has feet that size, and they are unused. If anyone needs them, please let me know (、．．)、