Nails nail structure is a product of human metabolism, its main ingredient is keratin (including proteins, minerals and carbohydrates, etc.) when passing a methyl group, is to be converted synthesis. 3-4 layers of keratin formed is our nails, nail itself is the body's appendages. Nails like skin can show the body's health, healthy nails should be smooth, glossy, round, full, slightly pink nail bed, face no spots, no ribbed no uneven phenomenon, the water content of about 18% , presenting a smooth curved surface, and has a certain thickness and hardness, strong and flexible. Nail growth cycle: fingernails grow about 0.08mm --- 0.12mm per day. About a month or so growth 3mm. Their metabolic period of about six months which is our ~ we can measure their nails under fingernails meets health standards Nail Oh Ningbo / Ningbo nail training / Zhejiang nail training / Nail Makeup / Nail eyelashes / arbor nail training