Our Injected tape extenisons are one of the most invisable tape extensions available in the hair extension industry, as the hair is injected into the polythene tape at the root of the hair extension. This allows the extension to mimic the look of the natural root.Making this method of hair extensions the most invisable in the market.Each pack contains 20 pieces of tape extensions 10 pairs/sandwiches.They are 2.5 grams per piece, 50 grams per pack. We reccomend 2 packs for fine to medium hair to achieve a full head.For medium to thick hair from 2-3 packs. For thick hair 3-4 packs.1 pack will be sufficient for fillers/volume and for very fine hair 1 pack is even enough to add length also. The hair is double drawn and will last from 9-12 months with correct aftercare.These tapes can be retaped up to 4 times. It is always a good idea to remember the extensions like our natural hair we dye blonde,the blonde can go faded so its a good idea to use silver shampoo on your blondes to freshen them up when needed.