Uses polyimide as an insulator outside, and the foil as an electric heating elements inside. During normal operation once the interior is within operating temps, the temperature is very stable. , and flexible polyimide heaters can quickly provide heat to where it is needed. Widely used in electronics manufacturing, scientific instruments. Polyimide film has excellent dielectric strength, excellent resistance to electric intensity, perfect heat transfer efficiency, and great resistance stability. Safe to use with stable performance. Equipped with self-adhesive can be fixed on the item surface easily.They are formated through high temperature high-pressure and heat-sealing process. Heating films can not control the temperature itself. You can use it with a temperature controller. Working Voltage: DC 24V Power: 72W Maximum Temperature: about 100. size: 140 x 20mm Material: Pi film colour: As Shown Package Contents: 12 x heating pad Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.