Salchow rosin has been an essential part of my viola accessories for over fifteen (yes, 15!) years now. I was introduced to it in their shop in New York City while trying bows. I was a Masters student at Yale at the time. I noticed how my old bow actually got better just by adding this rosin to it while trying other bows. It indeed is way more expensive then other rosins, but I have no doubt that it is well worth the few extra bucks/euros to get the Porsche of rosins. Sound gets crisper and deeper. Bow hair becomes more responsive with it than with any other. I was extremely happy to find it here on Thomann. I had not had a chance to go to New York for a while. My last rosin Salchow broke completely about an year ago. I used few others meanwhile. The difference is unarguably big for me. Thank you Thomann Music House!