Use Red Devil Caulk to seal around your windows and doors, and those little holes and cracks where your energy dollars leak outside. Just like closing a window you had open for a year, you can help cut your heating and cooling costs by up to 20% by insulating and sealing. Red Devil Caulk bonds quickly to wood, concrete, brick, metals, glass, tile, fiberglass, PVC and other plastics. It’s the only caulk you need.