... 1.,roof use,easy installation 2.high strength ,colorful 3.low cost good quality color roof ... demands of present various building style, such as easy installation, short building period, bump resistance, fireproof, ... for various climates, easy to be maintained, good endurance.2.it is light, easy to be installed and ... . It can be recycled and good for environments.7.it is easy to be used and transported, ...