It was recognised around the late 1940's that rot was a major floor in the Flag design due to poor box ventilation and proximity to the ground. To combat this the PMG workshops came up with the idea of adding air flow as trapped moisture was a huge factor in the rotting process. The Vented Flag Style box has venting panels located at the bottom and top of every window panel to assist air flow throughout the cabinet. It was mounted off the ground on mounting brackets or "feet" to further provide air flow and prevent rising damp. The door handle used was the larger stainless handle also commonly found on the NSW Temperate Dome Roof model. Apart from these minor modifications the vented flag style box remained almost identical to the original flag design in every other way.