A Great little gadget for those of us who like the instrument to feel more securely gripped. This thumb rest fits on all of my Descant Recorders and none of them are Aulos, so don't be put off by the brand. The only down side I found was that the inside edge had a slight burr which left a tiny scratch on one of my Wooded instruments, but this was quickly taken off with a needle file and now I move it from one recorder to another without any problems. This product is ideal for those of us who are getting a little older, as once in position it locates your right hand in a perfect position to suit the finger holes. I highly recommend this to any Descant Recorder Player.