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XHHW - high temperature (90C) chemically cross-linked polyethylene jacketed small diameter building wire.

XLP - Cross-linked polyethylene

XLPE - Crosslinked polyethylene is a thermoset and is crosslinked by radiation, thermally, or by moisture. XLPE offers a wide range of operating temperatures, excellent deformation, abrasion, and flame resistance. XLPE can be formulated with halogenated or non-halogenated flame retardant packages. Some grades are also rated XHHW-2 which offers excellent wet electrical properties.