- The switch is a green one at the back of device.Turn on the switch, the display will be on, then the power is on. The number shown on the screen is mixing time. - Digital controller of both time and speed: it is in the front panel. - Start the device once, it works once. If pause needed, just keep pressing the Start button for 3 seconds. once, it works once. If pause needed, press the button too. Safety lid and capsule clip: open the safety lid, fit the amalga capsule, glass ionomer or other material into the clip, while working, the safety lid must be closed.