A rubber heater is a planar heating element shaped into a single sheet that consists of heating wires sandwiched between 2 highly flexible silicone rubber sheets. Products are available with a maximum operating temperature of 250°C, while others come with double-sided tape for attachment. The thinness of about 1.5 mm and flexibility of these heaters enables them to be wrapped around containers such as drums, pails or canisters to heat the contents from the outside.