Wire-Nut® is perfect to twist-on with fingers for a secure connection that will last. The refined wire range makes it the best choice for fine stranded wire applications. The Wire-Nut® also features a tough, flame-retardant thermoplastic shell that withstands environmental extremes and is reusable for easy circuit changes and addition. High-Temperature models are designed to withstand the extreme heat build-up found in high-wattage light fixtures and signs.