Abstract: A hinged hold-open assembly for roof ventilator lids is provided, comprising a pair of hinged assemblies attached between the lid and a vent base, wherein each hinged assembly includes a hinge member; a retainer bracket affixed to the vent base, wherein the retainer bracket includes an extended member having a plurality of position holes corresponding to a closed position and a plurality of open positions; a position arm affixed to the lid, wherein the position arm includes a locking hole alignable with one of the position holes of the retainer bracket; and a locking device adapted to insert into both the locking hole and the position hole when said holes are aligned.