As has been previously mentioned, Nanogen hairfibres are excellent, there is a new one out now which i use called Caboki, it's different to the other fibre concealers in that the fibres stick to the hair and don't migrate to the scalp as much... Iv'e used most of them and this one for me anyway is the best,and is the only reason i wear a small hairline unit, instead of a topper...

My advice...try Caboki or Nanogen first before you take the hairpiece plunge...