GENOSYS EYE ROLLER - Clinical Models needle length size: 0.25mm. Medical grade stainless steel needle. Diskneedle type secure 100% safety form pin-off risk during the procedure. PLEASE NOTE: Microneedles longer than 0.50mm are for Medical use only. Many states may allow an aesthetician as a person to perform this procedure under proper medical supervision; however, the regulatory board does not cover this under an aesthetician license. Please check your state board regulations.