From Yamaha:

"For those who are serious about clarinet performance, but need to keep an eye their budget, the 650 is an excellent choice. The specifications of its bell, barrel, tone holes and other features are close to those of the top-of-the-line Custom SEV model. As a result, its sound is warm, round, and deeply resonant. Whether you’re a student of the instrument, or play professionally, you’ll find the YCL-650II to be the best clarinet for the price.

Constructed of carefully selected and seasoned Grenadilla wood and boasting an enormous amount of handcrafting and hand-finishing, the 650 features tapered tone holes that are undercut by hand for precise intonation and superior tonal balance. You’ll also find beautifully sculpted keys whose touch has been regulated by master artisans for perfect balance.

After extensive testing with an emphasis on sound, Yamaha selected top-quality leather pads. These pads allow breath to flow easily and stress-free while making it easier to produce beautiful, warm tone. Because the surfaces of the pads don’t vibrate when the instrument is played, no spurious pad noise occurs and breath flows directly toward the bell for outstanding projection.

The YCL-650II professional model clarinet features a new 65mm barrel design that produces a focused tone and quick response. Players looking for the tools necessary to maximize their performance will do just that with this clarinet.

Since there are so many different sizes and shapes of hands, it only makes sense to include a way to accommodate for different hand positions. That’s why you’ll find an adjustable thumb rest specifically designed for player comfort, while needle springs provide faster key action.

A great clarinet should also be easy on the eye – and the YCL-650II certainly is. The unique, natural finish that accompanies this beautiful-sounding instrument is bound to capture any audiences' attention.

In the 650, you'll find longer E/B levers. Additionally, the C#/G# keys are featured. This design reduces the likelihood of fingers slipping off the keys, improving performances, and lowering the chances of mistakes."