Harcon 400mm Continuous Roll Out Rafter Eave Vent Tray - 6m Length Description The rafter tray maintains a clear air space of 25mm from the eaves to the roof void, by creating a barrier for the roofspace insulation. Features Structurally profiled. Better rigidity than standard continuous rafter trays. Maintains a full 25mm air path down the line of the roof. 400mm deep. Will cover a 200mm depth of insulation at a minimum 30 pitch.