The Lachlan Clarinet Thumb Rest reduces tension, increases relaxation and endurance and promotes correct hand position. You'll never play the clarinet again without it! The Lachlan Thumb Rest eliminates the "pinch" tension between the thumb and fingers by simply opening the hand up. The increased openness promotes the needed relaxation without throwing the thumb and fingers out of balance. The curved fingers promote a much more efficient finger motion and increased endurance.