I bought a set from this guy at this years Bath and West show in Shepton Mallet.
The first time I used them today on soft ish metals (steel and Brass) the bits shredded and are useless.
This appears to be a scam but he is there every year so I will be patient and surprise him next year. I am not going to pay to return faulty goods. Rip off city!
'Avoid like the plague' would be my advice based on my experience!!