Karolo ea ho futhumatsa ea motlakase ea tube ea ho futhumatsa ka ontong ke tube ea tšepe ha khetla (tšepe, tšepe e sa hloekang, koporo, joalo-joalo), le terata ea spiral electric thermal alloy (nickel chromium, iron chromium alloy) e ajoa ka mokhoa o ts'oanang haufi le axis e bohareng. ea tube. Sekheo se tlatsitsoe ka magnesia a crystalline a nang le mocheso o motle le conductivity ea mocheso, 'me lipheletsong tse peli tsa tube li tiisitsoe ka silicone ebe li sebetsoa ka mekhoa e meng. Karolo ena e futhumatsang ea ontong e ka futhumatsa moea, hlobo ea tšepe le lino tse fapaneng. Tube ea ho futhumatsa ka ontong e sebelisoa ho futhumatsa mokelikeli ka ho tsamaisa ka likhoka. E na le litšoaneleho tsa sebopeho se bonolo, matla a phahameng a mochine, ts'ebetso e phahameng ea mocheso, ts'ireletso le ho tšepahala, ho kenya habonolo, bophelo bo bolelele ba tšebeletso joalo-joalo.