The H2 aluminum system is a direct bolt-on system, No drilling is required. The system is clamped onto the existing drip/gutter rails. It will fit both standard and extended version vans. Maximum load capacity is at 750 lbs for the aluminum system. The full system is constructed from extruded aluminum. The system is available in powder coated black, white and silver. The side rails are reinforced and stands at 5.5 inche in height. The side rails also has a built-in channel to allow additional accessories on the bottom. Cross bars dimensions are 2.25 inch x 1 inch. Cross bars are also extruded aluminum and has built-in channels on both top and bottom on the entire length of the cross bar. All Cross bars are oblong shaped to prevent wind noise during transit. It is aerodynamically designed for fuel efficiency in mind. Rubber handles are placed on both front and rear of the system to allow easy access and wind noise reduction. All Hardware are stainless steel. Cross bars come in several sizes pending on vehicle make, model, and year.