This ceramic wire connector is suitable for a wide range of high-temperature electrical applications and solves melted wire nuts. | Specified instead of plastic for applications above 200 degrees F, Maximum working temperature of 1,000 degrees F. | There is not a metal coil inside, Instead there is a substantial and sharp tapered thread cast into the ceramic. | 20 Pack Large Ceramic Wire Connector, Large Size 18-8AWG, High Heat Splicing Wire Porcelain Wire Nuts | The large size is roughly equivalent to standard red large wire nuts.