1). safe and reliable: Xiao Yi chorus of each row of the top units are equipped with safety rails, and it is a fixed component. This is to ensure that no leakage of the security fence installed, it will not be troublesome without installation. In addition, one-inch horizontal cover plate can prevent accidents. And there is no gap between the different components will not cause heel into. Xiao Yi chorus station connector between components of each component reliably fixed together, and will link the different frameworks.