Self-fusing silicone tape. Stretches 300 percent. Withstands a temperature range of -65 Fahrenheit to 500 Fahrenheit. Insulates 8,000 volts per layer. 20 mil x 1 inch wide x 10 feet roll. Also seals fuel and coolant leaks. Once you use it, you’ll ditch that old roll of electrical tape. I keep a roll under the seat of my touring bikes for roadside emergencies. It’s also great for replacing old electrical wiring sheaths.