※ I've only worn these once outside. The opening is narrow. ※ There is a small, rubbery-looking black stain on the inside. It might come off, but I haven't tried anything because I don't want to damage the fabric. I hope you can try to remove it yourself. Please purchase only if you understand this. These are khaki slip-ons, characterized by a combination of synthetic fiber and rubber. They are waterproof. - Brand: GERRY - Size: 22.5 ※ Narrow fit & stiff fabric, so these are best for people with narrow feet. - Color: Khaki - Material: Synthetic fiber/Rubber Thank you for looking!