Features: Round button design, one key to turn on, adjust power. Fall asleep easily every day The use of this product can stimulate the neurotransmitter of the cerebral cortex through micro current to regulate emotions, thereby promoting sleep. Using this product, the hands can be properly stimulated, so that the same hand and brain frequencies can be used to relieve anxiety. Small and convenient, you can take it with you. Suitable for people with insomnia, overthinking, etc. Description: Product material: ABS+stainless steel Product size: 60mm*40mm(1in=2.54cm Power supply mode: AAA battery (Safety transportation does not include battery) Number of batteries required: 1PCS*AAA battery Package includes 1 * Help sleep 1 * Manual Notes: Please allow 1-3mm error due to manual measurement. pls make sure you do not mind before you bid. Due to the difference between different monitors, the picture may not reflect the actual color of the item. Thank you