If you need electrical connectors that are unaffected by water, chemicals, vibration, temperature or dirt, and that will not come apart accidentally, then you need MSD Weathertight Connectors.

The Weathertight connectors are molded from a special nylon material to withstand temperatures from -40º to +257ºF and are indexed to prevent mismatching. Positive locks let you know when the connectors are completely joined by producing an audible CLICK. No click means no connection and they can vibrate apart.