This Systems will not spoil the appearance after cable laying, since the tray is made with small holes so that the cable is not conspicuous when observed from the bottom side. Systems oval and round holes alternately located on the bottom plate. Therefore, nylon bands or other suitable means can be fastened in arbitary positions. Damage to cables is minor at the time of cable laying and smooth laying work can be accomplished. The only reason to select a ventilated trough cable tray over a ladder type cable tray is aesthetic. No dropping of small cable is visible. The ventilated trough cable tray provide more support to the cables than the ladder cable tray does but this additional support is not significant. It doesn't have any impact on the cable record or life.