Ductile Iron Manhole Cover, Tempered Glass, Insulated Glass manufacturer / supplier in China, offering Square-Shaped Outer and Round Inner Ductile Iron Manhole Cover. The Factory Price of The Manhole Cover Is Designed for Safety and Anti-Theft in The Tunnel,, Top - Grade Tempered Glass for Refrigerator Shelves: Cold - Resistant Material, Keeping Your Food Fresh and Organized, Heat-Strengthened Glass for Enhanced Thermal Resistance and so on.