The fabric used is called "hopsack." The name comes from the hemp sacks used to carry hops, the raw material for beer. The fabric, woven in a rough plain weave, looks cool and is also highly breathable, making it a popular choice for men's suits. The weave has a unique unevenness, giving it a casual impression, while the use of matte yarn also gives it an elegant look. The material is a T/C blend of 65% polyester and 35% cotton, the same as the standard series. This hybrid fabric combines wrinkle-resistant and quick-drying polyester with breathable and absorbent cotton. It is resistant to shrinkage and deformation after washing, and it keeps the beautiful silhouette of the purchase. For wearing a hat for long periods, a slightly more relaxed size is recommended. A just-fit hat can cause various discomforts, such as headaches and itchy scalp. Therefore, this series sets the M/L size at 59.5cm, which is slightly larger than usual, and is designed to be adjusted to a comfortable fit using the hat's sweatband (the back of the inner tape) when worn. The size can be adjusted smaller by 2-3cm by pulling the Velcro part on the back, allowing you to choose a comfortable fit for various situations. The 510-type casquette is a variation design of the 530-type, which is characterized by its round silhouette when viewed from the top. Among the casquettes offered by CPH, the 510-type is the second most compact size after the 502-type. The silhouette is almost a perfect circle when viewed from above, and the front is shallow while the back is slightly deeper, pursuing a natural fit. The volume on both sides is also moderate, creating a round silhouette that is characteristic of a casquette and can be worn without being conscious of it. In addition, the 510-type has a well-balanced, moderate volume, so the casquette itself does not become too large, making it a classic model that even beginners can easily incorporate. Because of its basic design, its moderate fullness enhances the traditional atmosphere.