The Vantech H3 System is a clamp-on system requires no drilling for installation. The system clamps onto the existing drip/gutter rails. The cross bars are 3″ x 1.5″ heavy duty reinforced extruded aluminum. Cross bars have built-in channels for additional accessories. The mounting bases are aluminum at 3mm thick and 8″ wide for better support and grip. 2X 3/4″ Eyehooks are located on each mount and 1X 3/4″ eyehook is located on each side support. The side supports are made from 14 gauge steel. It is also galvanized then dipped in rubber for additional protection.