Please long-press the ON/OFF button (hold for 3 seconds) to turn on the device and click again to start the treatment. You will see the LCD screen illuminated, and a red laser beam coming out from the laser probe during the treatment. For Knee, Shoulder, Back, Joint, Muscle Pain, Arthritis, and Sciatica Pain. We suggest using the device twice a day and about 20 - 30 minutes each time. At least 4 hours interval between.