The H2 Aluminum system is a direct bolt-on system, Drilling is required. Maximum load capacity starts at 750 lbs for system with 4 mounting bases. Additional pair of mounting bases will increase the weight capacity by 250 lbs. The system is powder coated black or gloss white. The cross bars clamped onto the bottom or top of the side rails. Cross bars dimensions are 2.25" x 1in 14 gauge. The A286 crossbars are reinforced aluminum with channels and are designed to reduce wind noise. It is aerodynamically designed for fuel efficiency in mind.