Fusion hair extensions also known as hot fusion or U-Tip, is one of the oldest and more popular methods. Now with our new 1 gram strands you can get an even fuller look. Our regular fusion extension strands are 0.8 grams and also give you a beautiful look with a little less fullness. Our keratin bonds are easy to work with and hold extremely well. Fusion U-Tip Extensions are applied by melting keratin to grouped strands of hair. U-Tip Extensions can be worn up to 6 months before any need for reapplication.