I am using online Super Socks. The size is 25 cm. I am using 6-ply yarn, which is a bit thick. When laid flat, the length from the opening to the heel is 15 cm. Made of 75% wool and 25% polyamide. If using a top-loading washing machine, you can wash them inside out in a net with warm water up to 40°C. Do not use a dryer. (For drum-type washing machines, hand washing is recommended as they are prone to deterioration and pilling.) These are handmade by an amateur, so please understand. (Please refrain from purchasing if you are sensitive or seek perfection) - After receiving the product, please try them on and let me know how they fit via the transaction message. - No returns or exchanges.