This is a short, ankle-high foot warmer made from a special wetsuit material. You use the included funnel with a screw-on cap (as shown in photo 5) to pour hot water into it. You can even walk around while wearing it. Color: Black Size: M (27cm) - Fits foot sizes between 24-27cm Retail Price: ¥14,700 Set Includes: Main Body (1 right foot, 1 left foot) Funnel with screw-on cap Instruction Manual Regarding sizing, this information is from the Croz website: -------------------- Sizes Size Chart XS 21cm S 24cm M 27cm L 30cm XL 33cm The standard sizes are S and M. Sizes increase in 3cm increments. The basic way to choose a size is to select the size that falls within the range up to the listed size. -------------------------------------------------------------------- Therefore, size M fits feet between 24-27cm. You can also adjust the warmth by controlling the amount of water you put in. Thank you.