Hardware: A.Functions: its openness, compatibility, portability, expandability, maintainability, safety etc must be considered. B. Craft: if molding, jointing and surface processing comply with international standard; if product shape is designed to comply with human engineering; if it has protective measures. C. Material: if housing is all-steel; if cables are made of fire-retarding, low smoke and halogen-free materials and are covered by protection materials.