1、PRINCIPLE: Microcurrent through the palm of the hand to the brain, enhance the brain waves, increase the secretion of neurotransmitters, purely physical action to help fast sleep, get a healthier and better quality sleep. 2、NEGATIVE ION: Negative ions are widely found in nature, and have the function of dust reduction and sterilization. It can promote the body synthesis and storage of vitamins, strengthen and activate the body physiological activities and has a sedative, hypnotic effect, so it is also known as the vitamin. 3、RELAXATION: Microcurrent is induced by the hand and transmitted to the brain stem through the body own nervous system, which in turn affects the activity of the frontal cortical layer and reticular system, promoting endorphins, melatonin and other neurotransmitters, reducing anxiety and increasing attention, making people feel relaxed. 4、RELIEVE: This sleep aid device mainly helps with insomnia, relieves stress, helps fall asleep, relieves stress and improves sleep quality. This sleep aid can slowly improve sleep, but requires half a month of continuous use. 5、PORTABLE: The sleep aid machine has a compact wireless design so you can use it anywhere, anytime. The lanyard can be hung on your wrist to prevent dropping and breaking. 6、USAGE: This sleep aid can be used for study, office, home and business travel, very safe to use. 20 minutes of daily use can relieve headache, help you overcome stress, anxiety, sleep problems. Item Type: Sleep Aid Device Material: ABS, electronic components Size: Approx. 88 x 42 x 22mm / 3.5 x 1.7 x 0.9in Battery: 5V 400mAh Lithium battery (built in) Charging time: 2h Levels: 1-9 levels 1 x Sleep Aid Device 1 x Lanyard 1 x Rechargebale Cable