OG has 5 intensity levels to choose from, this will allow you to select the most comfortable intensity level for you. We recommend starting at the lowest intensity and working your way up each session, if you get uncomfortable and/or get marks that last longer than a couple days it means that intensity is too high for you and the one below it should work best. Two Modes Explained: We realize that not all body parts are created equal, so we created two separate modes that will make your IPL hair removal journey that much simpler. #BeautyMadeSimple is our motto after all. Stamp Mode: With Stamp Mode, each individual click of the pulse button causes a flash. This is the default mode on your Handset, it is perfect for precision areas like the underarms, bikini area and face. Auto Mode: Hold down the pulse button away from your skin until all indicator lights are blinking. This will make the handset flash every half second it is in contact with your skin, without clicking anything. Please lift the handset after each flash to cool the bulb. To disable, hold down the pulse button until the lights stop blinking. Perfect to quickly and effortlessly treat your legs.