Weathertight Sealed Connector Kit MSD IgnitionMSD Weathertight sealed connectors are molded from a special nylon material to withstand temperatures from 40 to 257 degrees F and are indexed to prevent mismatching. Positive locks let you know when the connectors are joined correctly with an audible click, while each terminal has its own towerso there's no chance of shorting. And lastly, silicon seals prevent water, chemicals, and dirt from entering, for a truly reliable, maintenance free