M size. Recommended for shoes size 25-26cm. These insoles are highly absorbent, keeping your feet dry and comfortable. A printed guideline is included to easily check the finished size. Layer 1: Uses "quup-LT," a highly absorbent and moisture-wicking nylon yarn. Prevents stuffiness, reduces stickiness, and provides a cool and comfortable feel (antibacterial treatment). Layer 2: Uses "Poron," a high-performance special urethane foam with excellent shock absorption, which absorbs impact on the feet during walking and reduces the burden on the knees and lower back. Please cut to your desired size. The necessary chart is included. *The size chart is based on standard sizes and shapes. Sizes and shapes vary depending on the shoe, so please refer to the instructions on the back of the packaging when cutting. First, cut the insole larger than the size of the shoes you will be using, both in length and width. Adjust by cutting little by little while checking the size and shape. It is recommended to adjust while observing the size rather than cutting drastically at once. Caution: Due to the nature of the dye, the insole logo print cannot be completely colorfast. There is a possibility of color transfer due to friction or sweat. Please be careful when using with light-colored socks. Please note that the color may not come off depending on the degree of transfer. Nylon yarn / Urethane foam If you need a tracking number, I will change to Yu-Yu Mercari mail with anonymous shipping with a tracking number before you purchase, so please let me know before you buy. I will accommodate this for an additional 100 yen, including shipping. The following are my personal impressions and measurements: Thickness is approximately 3.4-3.5mm when laid flat. Because it is soft and has shock absorption function, it may become thinner than 3.5mm when worn.