Item Type: Handheld Sleep Aid Device Material: ABS, Stainless Steel Color: As Pictures Shown Weight: Approx. 136g / 4.8oz Battery Capacity: 500mAh Battery Type: Lithium Battery (Shipped with Built in Battery) Battery Model: 902030 Package List 1 x Sleep Meter 1 x USB Cable 1 x English Manual 1Relaxation Mode and Activity Mode: Place the sleeping aid in your left hand, and hold the device with your palm, so that the electrode is in the center position. When you feel tired and need more energy, we recommend using the activity mode. 2Good Effect: Using the hand held sleep aid device for 15 minutes every day can moderately relieve headache, help you get rid of insomnia, anxiety, sleep problems, and help you sleep well. 3Help Fall Asleep: This sleep aid device can help you fall asleep faster and relax completely during sleep. This is a good gift for friends with sleep problems. 4Applicable People: Handheld sleep aid device mainly helps people with insufficient sleep and poor psychological quality fall asleep as soon as possible. 5Light and Portable: Handheld sleep device is light in weight, small in size, easy to operate, fast in charging and convenient in use. Can be used in the office, at home and on business trips