Wide cast aluminum mounting base, available in XM3, XP3, and XP4 finishes. The XM3 bar features a stainless steel cross bar where the XP3 and XP4 features a powder coated cross bar. Designed to securely mount to the roof gutter. Can be mounted to many vehicles with internal gutters by using our stainless steel gutterless mount kit. All CARR light bars come with special bolts that are keyed to protect your investment.