Pre-bonded Utip human hair extensions also know as hot fusion, are in a class of their own. Their higher cost and time investment have their own rewards, which is why these extensions have their own committed fan club! Available for installation by a salon professional, U-tip strands are then glued into the hair. We sell 25x strands per pack. We suggest a minimum of 4 packs (100 strands) for a full head, however you may need more depending on how much hair you have and how much volume and body you require.