Features – Needle length: 0.2mm/0.25mm/0.3mm. – Color: black (handle)+purple (roller). – Material: medical-grade stainless steel (needle) and hard plastic (handle). – 100% brand new and high quality 540-Needles Micro-needle Roller Medical Therapy Skin Care Tool. – A common cosmetic procedure for treating many conditions by stimulating collagen and elastin production. – Stimulate the collagen production. – Improve elasticity of skin. – Smoothen acne scars. – Promote skin rejuvenation and improve alopecia. – Mildly roll 10 times vertically and horizontally. – Can be used on all areas of the face, neck and body and scalp. – Can be used by yourself anytime at your personal convenience. – Different needle lengths have different usages: 1. Home use: 0.2mm/0.25mm/0.3mm 2. Clinical use: 0.5mm/0.75mm 3. Medical use: 1.0mm 4. Physician use: 1.5mm/2.0mm/2.5mm/3.0mm – Cleaning method 1. Soak about 5~8 minutes with 75% alcohol. 2. Using ultraviolet to disinfect for about 45 minutes