I use ACTIV Aqua Bond 3 and i can wear my piece up to 3 weeks, but after 2 weeks want to reatach it. But i tested it and it holds up 3 weeks on my head, i only have to fix the edges after some days. Btw i sleep with the hair.

http://www.gfh-hair.de/Seiten/haarersatz...nding.html