China Tray Cable Tray Tray is a tray with many waist shaped holes at the bottom to facilitate heat dissipation; The bottom of the ladder is like a staircase, and there is a baffle on the side. The ladder is used in places with a lot of dust, which will not accumulate dust. Trough and tray are different at the bottom, with and without holes. The tray type is not good for heat dissipation. XQJ...