I had been looking for a good quality stopping mute after my previous one was accidentally crushed. A colleague in the orchestra I play in had one that looked good, and sounded great. To my surprise it was the same model that Thomann sell. As i was able to borrow his for a quick test i was more than happy to order it from thomann at a much lower price than he paid for his.
When it arrived i was once again impressed by the extremely high build quality of the mute, i am certain this will last a very long time indeed.
A few days later I was able to give it a really good test, playing Mahler's 1st Symphony. It was all I had hoped for, great 'sizzle' sound, and good tuning.