These tray systems allow excellent ventilation and prevent sagging while routing. Is your cable tray system optimized for safety, dependability, space and cost savings? Cable tray (or cable ladder) systems are a popular alternative to electrical conduit systems, as they have an outstanding record for dependable service, design flexibility and cost savings in commercial and. Hubbell Wiring Device-Kellems and Hubbell Premise Wiring are divisions of Hubbell Incorporated, a U. headquartered manufacturer with over 130 years of supplying solutions for the electrical and data markets. The mechanical and electrical characteristics, tests, certifications, overall quality management, recommendations mentioned.