Cross-linked polyethylene high-heat-resistant water-resistant (XHHW) building wire is a coated wire typically run through raceways. XHHW wire has a thicker and more protective jacket than THHN building wire, making it more resistant to chemicals, ozone, and abrasions. Its cross-linked polyethylene (XLPE) insulation is also more flexible than the thermoplastic insulation of THHN wire. This allows XHHW wire to bend and flex more easily, which makes it ideal for electrical projects where complex, close-spaced bends are required.