Why Choose Sassina Hair? Sassina team has been working on researching and developing extensions for more than 10 years, We have our own professional team in every single step of production, can customize a variety of styles of Invisible Line hair extensions according to your needs. We are committed to providing high-quality products and exceptional customer support. Your satisfaction is our greatest motivation. Why Choose Invisible Line Hair Extensions? Invisible Line hair extensions are one of the newest methods of adding length and volume to your hair. which is easy to hide with your own hair--no tape, glue, weaves, or beads are necessary. It takes just 20-30 seconds to achieve the perfect fit. You'll love it after trying. Invisible Line Hair Extensions Details FAQ about Sassina Invisible Line Hair Extensions. 1. Can I curl the hair extensions? Yes. Treat the hair as it is your own hair. Use a flat iron/straightener, but as with your own hair, never use hot tools too often. 2. Can I dye or bleach the hair? Yes. The hair can be colored. As a general rule, it is easier to darken the hair than to lighter the hair. Lightening and bleaching are discouraged for it results in damage to the quality of the hair. 3. How many pcs do I Need? If you have thick hair, we recommend 1 pack to increase weight and length. If you have thin hair, we recommend 2 packs to increase weight and length.