Our hair growth roller contains plastic, silicone, nylon. It can promote thinning hair growth, activate stem cells that produce new hair, stimulate dead hair follicles to regenerate, hair growth is rapid, and the average new hair thickness increases. Its use is simple: Start at the root and activate the stem cells that produce new hair while stimulating the regeneration of dead hair follicles; Hair grew 80 percent faster and new hair was 240 percent thicker on average; New hair appears, about 67% thick; Stable thick new hair, healthy thick hair. Promotes hair growth, nourishes scalp with strong roots growth, soothes and improves scalp for healthy thick hair.