Tried these as a replacement for the worn out felts for my Thomann FH 600 G Bb-Flügelhorn, but they are too thin and a bit too small. Instead I bought the Thomann Valve C.Felt A402 18,5x03,0 which fit this Flügelhorn much better.
Have just scored 5 stars anyway as they look good quality if they fit in a different horn.