The safety clutch SAK G 28 is used in conjunction with all toolholders with G 28 coupling. The safety clutch SAK G 35 is used in conjunction with all toolholders with G 35 coupling. It is a dead man switch allowing the flex shaft to disconnect from the toolholder at any time of operation. Lever should be engaged (depressed) while flexible shaft machine power switch (ON/OFF) is off. The clutch is of mechanical design and disconnects the drive from toolholder when safety clutch lever is released. The released safety lever protects from accidental start-up. Safety cut-out clutch for improved safety. Stops the handpiece instantly.