Feature:1.Built-in lithium battery 1800mAh2.Two control buttons (adjust vibration, adjust temperature)3.3 seconds rapid heating, built-in security chip4.3-speed intelligent temperature adjustment5.4-speed vibration massage6.Adjustable elastic strap with buckleSpecification:1.Material:Thickened ABS+deer velvet fabric2.Temperature and heat setting:50(122℉)/55(131℉)/60℃(140℉)3.Charging voltage:5V4. Li-ion battery capacity: 1800mAH5. Strap length: 65cm (with elasticity)6. Duration of simultaneous use of vibration and heating gears: 1 hour7.Use range: abdomen/waist8.Charging method: TYPE-C cable