The cable trays consist of a thin metallic plate and electro-welded steel rods. Their construction is based on the international standard IEC 61537, which specifies the requirements for cable tray systems, tests, and specifications. The alloy also contains molybdenum. The GB/T 34394-2017 standard covers classification, testing, packaging, and installation. Cable tray systems are defined to include, but are not limited to straight sections of [ladder type] [trough type] [solid bottom type] [channel type] cable trays, bends, tees, elbows, drop-outs, supports and accessories. ANSI/NFPA 70 - National Electrical Code.