1.Flat tip keratin pre bonded human hair extensions: About color：please refer to the color of the product instead of the model. There may be color differences because of monitors. 100 Strand/package, 2-3 packages for normal full head. Use of hot fusion. 2.Hot fusion pre bonded human hair extensions:A newer form of pre-bonded extensions,use of hot fusion for long-term attachment. Flat and thin shape,not easy to detect.Feel soft,covert and natural after using.A specific solvent allows you to remove the keratin extensions easily 3.About style: 100% remy human hair , NO mixed animal or synthetic hair. Can be straightened, curled, washed, restyled and be dyed-only to darker color. When you style your hair, the heating temperature should not exceed 180℃, which will make your hair look more natural 4.Hair use: Sunny Hair uses 100% human hair, the hair is silky smooth, and the hair life span of 3-6 months (depending on usage and care methods) 5.Extension cord weight: 100 Strand. We recommend 2-3 packs to increase the volume, and 3-4 packs to extend the length.U Tip Hair Extensions is a similar type of hair extensions