Features: Hand-held sleep instrument: apply low-frequency electrical pulses stimulate to the palm, conduct from the nervous system of the hands to the brain stem to realize the same frequency of the hands and brain, have a positive effect on neurotransmitters such as endorphins and melatonin, and make the human body more calm and relaxed. Calm the mood: Reduce stress in daily life and work to relax Invigorate the : the invigorate mode, get rid of troubles, improve concentration, double the efficiency of learning and work Portable Design: Compact and lightweight, easy to carry. Multi mode design: In different mode, it can better promote the rapid increase of neurotransmitters. Notice: 1.Actual color may be slightly different from the image due to different light effect 2.Please allow 1-3cm deviation due to manual measurement Description: Material:ABS Plastic Stainless Steel Process Size:6.5x4x3.5cm Built-in battery capacity: 300mAh Charging voltage: DC5.0V/1A Operating voltage: 3.7v Working current: 0.005A Rated power: 0.3W Rated current: 200MA Battery life: 2 hours Charging time: 1 hour Working gear: 15 Product weight: 27g net, 100g gross Product size: 6.5x4x3.5cm Package size: 10.4x9.3x4.1cm Packing list: Sleep meter x1, USB charging cable x1, manual x1 Package List: 1*15 Modes Handheld Sleep Instrument