It is sensitive so you put on the cup it works and you take away the cup it stops working automatically.It is safe and energy-saving. Heating you drink with this product is great. And it is suitable and type of cup.Made of high quality ABS and armoured glass, it is durable.Length and height of this product is 12cm and 2cm.It can be used to heat drink with cup.Item Name: Insulation PadMaterial: PlasticFeatures: Smart, Easy to Use, Temperature ControlPower Supply Mode: Alternating CurrentCable Length: 150cm Rated Frequency: 50 HzRated Voltage: 220 VPower Rating: 18 WIntelligent Constant Temperature: 40-60°Size Details: Length: 12cm/4.7" (Approx.) Width: 2cm/0.8" (Approx.)Notes:Due to the light and screen setting difference, the item's color may be slightly different from the pictures.Please allow slight dimension difference due to different manual measurement.Package Includes:1 x Insulation Pad