Whether it is a single high-hardness EPS or ordinary EPS used for helmet cushioning, it has its limitations. With the continuous development of EPS products and technology, the layered EPS material that combines two different density EPSs has solved the above problems. It can ensure that the EPS outside the buffer layer has higher hardness to resist energy impact, and at the same time, the internal elasticity is better. High EPS has better cushioning effect. In addition, there are other dual-density helmets, and the density of different layers is different.