This is an under-insole made using PORON. This is the 2mm thick type. This product solves the problem of: "I like my shoes and insoles, but I want to improve the shock absorption and cushioning a little more." You can improve the shock absorption and cushioning simply by placing it under your existing insoles. Since it is held down by the insole, it is unlikely to slip inside during use or while playing sports, but if you are concerned, please secure it with double-sided tape in a few places. It is made in a 28cm size, but for those with sizes less than 28cm, you can use it by overlapping your existing insole, aligning the heel side edges, marking the protruding part of the toe with a pen, and cutting it. This is a 2mm thick type, so the size feeling inside the shoes will remain almost unchanged, but there is a possibility of some tightness in tight-fitting shoes. For tight-fitting shoes, the PORON half insole, which is sold separately, is recommended. You may feel a little tight before use, but PORON will compress and conform to your weight to some extent. We also offer a 3mm type for shoes with a little extra room in terms of size and foot shape. This is not an industrial product, but a handmade item, and it is cut from PORON sheets by hand with scissors, so there may be some waviness on the cut surfaces and marks from the pattern making. Please understand this in advance. There is no problem at all with use. It can be used not only to improve the cushioning of sports shoes but also for sneakers. Basically, we cannot offer a discount, but we can offer a small discount for bulk purchases. Thank you. ※Because PORON has the property of becoming a little harder at low temperatures, if the outside temperature is low, you may not feel the full effect. If you are concerned, please warm it with a hand warmer before playing.