A beret is a very popular hat in autumn and winter seasons, fashionable and elegant, and can effectively complement a girl's temperament. Many girls are fond of it. However, while berets may look good, they do not have the structure of adjusting the size of the hat with a tail buckle like commonly seen baseball caps. Moreover, they do not have the structure of a knitted cap or a pullover cap that can deeply secure the head. Therefore, when wearing berets, we often encounter the problem of unstab