... , Impact resistant, and Anti-rust, weather-ability, insulating, durable (30years), Locking option. Anti-abrasion:fibreglass content above 28%,when demage,no ... the cast iron one, and 1/2 of the BMC with steel one. Convenient for transport, security check, install,open and ... intensity.5.Appearance: Physical appearance to be nice, smooth, good elastic curve, no distort, easy to open. the cover should not ...