200-300 strands( 2-3 sets) for a full head of hair depending on how thick your own hair is. you can use 50-110 strands to highlight your own hair . or make thin hair to thick. Material: These hair extensions are made from 100% real human hair,which is soft and silky, also, can be permed, straightened and washed. Size: 15" 16" 18" 20" 22" 24" 26" 28" 30" 32"; Weight: 100g 100strands 1g/s. Hair Care: 1. Pls wash it by some mild, proper shampoo recommended by a local professional hairdresser. 2. Be gentle, especially when you comb your hair extensions. 3. As the hair can no longer get nourishment and moisture from roots, also, they have been dyed to achieve the current color, extra nourishment and care is quite important for a good look and longer lifespan.which can vary from 3 to 12 months depending on care and usage 4. While the hair can be re-dyed, self-dyeing is not recommended unless by an experienced professional hairdresser, as re-dyeing requires particular skills and dyeing products.