I was wearing those for a year till today. I don't know why but my wrist become itchy.
The small one is made by myself from a threads bought during my Manaslu Circuit trek in Nepal - I've done similar, but in different colors, also for my 3 friends. Each of us has her main color base :) The longer one I've bought in Boudhanath - the biggest stupa in Nepal in Kathmandu. It's the same kind of thread as one monk gave me 7 years earlier, also in that place. And it was not so easy to find new one.
...I feel somehow strange not wearing them after such a long time...