They're fastened in just like other extensions. Each natural hair extension has an individual feather affixed to the bottom and is braided and attached to your real hair using a small bead like a regular hair extension (no glue, heat or weaving is involved in the process).
For a subtle look, you can choose a feather that blends in with your hair, while a bolder, rocker-tinged ‘coif
is easy to create with brightly-colored feathers and multiple extensions.
I've gotten some different time quotes on these things... anywhere from 8 -10 weeks from one source & 4 months to a year depending on care. The feathers can be straightened, blow dried, curled, and gently brushed and the feathers color does not fade.