The material of VAN'shigh low bike rackis galvanized steel pipe and great for outdoor use. The usage of high and low parking rack is saving the bicycle parking space. The high low bike rack is freestanding, but it's need a pre-drilled base ground fixed and a pre-drilled base ground fixed.VAN provides a variety of styles and specifications about the high low bike stands, providing a variety of capacity to choose like 2 bikes, 3 bikes, 4 bikes, 5 bikes and 6 bikes.