The line of ILME rectangular multipole connectors includes enclosures specifically made for aggressive environments. Sometimes referred to as heavy duty, or W-Type, they feature a unique black painted finish that is made for use under harsh conditions, offering a more ideal solution than standard aluminum enclosures. The black finish takes the place of the green finish that is seen on older versions. They are particularly useful in more extreme conditions, especially where exposure to corrosive substances is a concern.

With an ingress protection rating of IP69K, these enclosures are not only protected against dust, but also from high pressure and high temperature water. Being resistant to corrosion, they are useful in salty environments and other work areas that have harsh chemicals in close proximity. The epoxy polyester powder finish that is oven painted works better against tough chemicals than epoxy polyester. Compared to the green versions, the black finish enclosures have 50% greater resilience to salt. This is due to the chromate die-casting process. They are compatible with all types ILME rectangular inserts, including the CME series. The gaskets that come with these enclosures are made to be oil and fuel resistant, while the supplementary insulating strips provide additional protection.

Because of their design and construction, they are able to stand up to stresses and impacts. The W-Type enclosures that have levers make use of the 'classic' style. The full line of ILME connectors, including the W-Type enclosures, is available through Major Electronix over the phone or through the website.