The BEHN Thumb Cusion is available for a variety of thumb rest designs.  It simply slips into position and is easily removable for storage at the end of your session.  
 
Support your clarinet with ease - no more thumb pain
Egonomically contoured for a large contact area.
Distributes the weight of your clarinet over a larger surface area on your thumb
Much more comfortable
You'll be able to play for a longer session before fatigue becomes an issue
You'll have instant improvement in your technical facility
Helps improve your natural hand position for better dexterity
Available with 3 optional pads for a soft, a softer, and cloud-like cushioned experience
Available for Buffet Adjustable thumb rests, Standard traditional non adjustable thumb rests (for most makes), Selmer Signature thumb rests, and Rossi thumb rests. More to come in the future...