i totally recommend the DIVYA Clip-in's, it is one hair product you want to invest on. I say invest because the price is a bit high and the product is excellent because it last for months and you can reuse it over and over again.
DIVYA Clip-in extensions are for DIY or Salon use, you can clip them in how you want for length or volume extension or you can leave it for the professionals, a wash and treatment in two or three weeks will make them even last longer. seen them from a friend, oh how i would like to have one of my own. :)