IVYSCULPT PRO hand-piece is with intelligent temperature sensor to ensure laser safety. there are 4 temperature probes to monitor whether you have attached the hand-piece on the skin tightly. 1060nm laser is invisible by bare eyes, when customer do treatment they will be not sure about whether laser its working or off, so we add indicators to ensure laser working safety. When the hand-piece touches body skin tightly,there will be green light, then machine can work lasers. At the same time, the indicator green light will be changed into the blue.