Hi-Temp twist-on wire connectors specifically designed to withstand hi temperature and other tough environments. Manufactured with high-temperature-rated plastic that is grooved for comfortable twisting. Designed for copper to copper wire connections from #18 to #10 AWG. Please see packaging for detailed listing of all wire combinations and ratings.Temp. rated to 150 deg C (302 deg F)Black color designates hi-temp ratingComfortable grip for easy twist-on applicationPerforms in environments of extreme temperatures without failing to protect wire connectionRated at 600V max in building wire and at 1000V max in lighting, fixtures/luminaries and signs