On this site you can see musicians who are using the belt already for quite a while. You see pictures and videos.
On this video you can see Willi Brandstoetter using his tubabelt.
Pictures are following...
Here you find the way to Mnozil
Some more videos where you can see Willi using the belt are on youtube.
Here are some links:
How easy the system works you can see on this video. At about 10:40 you see her hanging the tuba onto the belt.
On this video you see Marie-Theres Stickler with ALMA playing her accordion with belt.
On the next video Andreas Maurer is using his belt for playing his accordion. You can find the band Faltenradio hier.
Joseph - thank you for this video! Joseph´s website you find here.
Joseph founded the "Mouthpieces For All Initiative" (MPFAI).