If you have a Boundless Tera, CFX, CF, CFV, CFC Lite and Vexil, click the 'POWER' button five times in consecutive order to power 'ON' and 'OFF'.
If you have a Boundless Terp Pen or Terp Pen XL, the sensor is activated by inhaling through the mouthpiece. Essentially, the device will ONLY heat once you begin inhaling.