These bulbs did not live up to my expectations. Two of them have already exploded. They say it's for the big heater but it doesn't heat the whole plate. Only the middle wax has melted, all sides have hardened after two days of use. They can be larger for medication or a small heating pad. I don't even smell the wax. The wax I have is usually very strong. Sitting next to him, I only smell him when I turn my head towards him. I would not buy these again