The helmet is composed of a cap shell, a cap lining, a chin strap, and a rear hoop. Each ring is very important and is
mutually related. The cap shell is usually semi-circular, very smooth, and has a certain degree of elasticity, so that when an object above the head falls, it can form a good cushioning effect, and there are many between the cap shell and the cap liner. The free space can instantly disperse the huge impact force, thereby reducing the hazard to the head when danger occurs. Therefore, the safety helmet is a labor protection product that many construction sites must wear.