Jupiter Clarinet JCL-631NMO It's a standard 6 ring / 17 key instrument. It has a heavy-duty crow's foot for the right-hand keys, an important feature. It also has an interesting detail in that the linkage has a nicely made tiny ramp both sides of it which means that you can actually twist on both sections without depressing the second ring of the top joint. This Clarinet has a very well made adjustable thumb rest. The setscrew clamps down on a rod that also has a ring for a neck strap if needed. The thumb rest itself is oriented towards the hand, a nice feature.