This is a specially designed cover for the head circumference that fits gently. The material is water-repellent twill fabric (35% cotton, 65% polyester). It's an easy-to-handle material that quickly repels water while absorbing steam from sweat and drying quickly with less wrinkling. Because it's for your precious child, we've prioritized a balance of functionality and gentleness. ・Dark colors may fade during washing. We recommend washing them separately with a neutral detergent.