The connectors are made of a nylon material for the best combination of temperature resistance and flexibility. Browse heat shrink and twist-on options. Weather Pack is an environmentally sealed electrical connection system designed to withstand exposure to extreme temperatures, moisture, and harsh engine compartment fluids and chemicals. They are extensively used in severe duty applications including racing, construction, off-road, and industrial. From corrosive environments to extreme weather and mechanical stress, industrial machinery relies on rugged, IP-rated connectors and connectivity solutions for uninterrupted performance.