A container system for medical instruments comprising a molded plastic reticulated tray composed of a continuous rib that forms a tray rim and a plurality of intersecting ribs defining large openings therebetween. The intersecting ribs are dished and have opposite ends connected to the continuous ribs at spaced apart locations therealong. The plurality of intersecting ribs also have rounded surfaces so that a washing or cleaning fluid directed at the plurality of intersecting ribs from the outside, upon flowing through said openings will follow and intimately contact those rounded surfaces so that those surfaces are cleaned thoroughly. A preferred embodiment of the system also includes a reticulated cover releasably connected to the tray and various brackets for fixating instruments in the tray.