If you have any inquires or any questions, please feel free to contact us by email or online, We will get back to you within 24 hours Hydra roller is a good method that helps solution take effect inside the skin. It is micro needle device for delivering cosmetic and hair growth solution into the dermis by lightly tapping it on your skin especially around eyes. 20ea of micro needles with the same hair thickness forms fine holes in the skin without pain . Also Special spiral system is designed on each of those micro needles through which the solution flow down and can be transferred into dermis very directly.syi