Cable trays vary in size in order to accommodate varying numbers of wires. International projects are most often made in widths of between 50mm and 900mm and depths of between 50mm and 150mm. When choosing the size of cable tray, it is a tradeoff between the existing volume of cable and the future volume of cable. It is grounded on 40 years of experience in the manufacturing. In practice, cable tray dimensions are a system of interrelated measurements —width, depth, length, and material thickness—that directly affect cable fill compliance, heat dissipation, structural loading, and long-term expandability. Heights typically range from 25mm to 150mm, depending on cable volume and application requirements. In US practice per NEMA VE 1 (referenced by NEC. The B-Line series Cable Tray Manual was produced by our technical staff.