These versatile and industrial-strength heaters can be used on a wide range of surfaces and environments due to their flexibility, moisture / chemical resistance, and ruggedness. They easily install on everything from laboratory vessels to large vats and tanks - ideal for solving viscosity, freeze protection, and process control heating applications. The unique grounded heating element is laminated between two layers of extra strong 20mil fiberglass reinforced silicone rubber. Heaters for metal surfaces have faster heat-up rates due to the 2.5 watts /in2 power density.