Mica surface heat mats are suitable for temperatures up to 300 deg C although they are limited to 150 deg C due to the maximum temperature the adhesive backing is suitable for.
They are available in several sizes and are a robust lower cost alternative to silicone heat mats which are more resistant to moisture and splashes.
These type of heaters have a rigid design and there for is more suited to flat surfaces. The resistant element is fully sealed within the mica which ensures proper heat transfer.
They are easily to install and are supplied with 2 leads pot-sealed for mains connection.