The Evans Torque Key is a drum key with a comfortable grip and a handy knob to tune your drums "fingertight". But... that is not what makes this key special.
That is the mechanism on which you can set how tight you want your drums to be tuned. Once you're set you can start tuning and when you reach the desired tension, the clutch will pop off! This way you can quickly bring all turnbuckles to the same tension without making any noise. Ideal for the stage!