I apologize for not responding back sooner. I haven't had the time to look at The Woodwind Forum page in a little while. However, The Deluxe WAW Modified Thumb rest for Alto Sax will fit on the Yahmaha Alto Sax as well as the Henri Selmer Mark VI Alto. I haven't physically tried it on any other makes, however, most horn manufacturers pretty much have copied the overall design of the Selmer Mark VI, so I believe it will most likely fit pretty much most of the Alto Sax horn manufacturers Alto Horns. Thank you for your interest, hope you will try one out. Be well and Stay Blessed!