Features: 1.The product adopts a simple oval design with a new matte texture, which conforms to the design of people's hand grip, simple and comfortable. 2.Button design, one button to turn on, adjust the power supply. Fall asleep easily every day 3. Sling design: easy to carry and use 4.Using this product can stimulate the neurotransmitter of the cerebral cortex through micro-current to regulate emotions, thereby promoting sleep. 5.Best gift choice for your family/friends. Notice: Actual color may be slightly different from the image due to different monitor and light effect Please allow 1-3cm deviation due to manual measurement Asian size is smaller than eu/us/uk size,please compare the detail sizes with yours before purchasing. Description: Massage principle: vibration Color: silver Battery:1x AA Battery(not included) includes: 1x Sleep Helper